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1.
Nature ; 617(7962): 738-742, 2023 May.
Artículo en Inglés | MEDLINE | ID: mdl-37100919

RESUMEN

Cities are generally warmer than their adjacent rural land, a phenomenon known as the urban heat island (UHI). Often accompanying the UHI effect is another phenomenon called the urban dry island (UDI), whereby the humidity of urban land is lower than that of the surrounding rural land1-3. The UHI exacerbates heat stress on urban residents4,5, whereas the UDI may instead provide relief because the human body can cope with hot conditions better at lower humidity through perspiration6,7. The relative balance between the UHI and the UDI-as measured by changes in the wet-bulb temperature (Tw)-is a key yet largely unknown determinant of human heat stress in urban climates. Here we show that Tw is reduced in cities in dry and moderately wet climates, where the UDI more than offsets the UHI, but increased in wet climates (summer precipitation of more than 570 millimetres). Our results arise from analysis of urban and rural weather station data across the world and calculations with an urban climate model. In wet climates, the urban daytime Tw is 0.17 ± 0.14 degrees Celsius (mean ± 1 standard deviation) higher than rural Tw in the summer, primarily because of a weaker dynamic mixing in urban air. This Tw increment is small, but because of the high background Tw in wet climates, it is enough to cause two to six extra dangerous heat-stress days per summer for urban residents under current climate conditions. The risk of extreme humid heat is projected to increase in the future, and these urban effects may further amplify the risk.


Asunto(s)
Ciudades , Clima , Trastornos de Estrés por Calor , Calor , Humedad , Lluvia , Humanos , Ciudades/epidemiología , Calor/efectos adversos , Tiempo (Meteorología) , Humedad/efectos adversos , Factores de Riesgo , Trastornos de Estrés por Calor/epidemiología , Trastornos de Estrés por Calor/etiología , Trastornos de Estrés por Calor/prevención & control , Población Rural , Modelos Climáticos , Población Urbana , Estaciones del Año
2.
Annu Rev Public Health ; 45(1): 315-335, 2024 May.
Artículo en Inglés | MEDLINE | ID: mdl-38166501

RESUMEN

Climate change poses a significant occupational health hazard. Rising temperatures and more frequent heat waves are expected to cause increasing heat-related morbidity and mortality for workers across the globe. Agricultural, construction, military, firefighting, mining, and manufacturing workers are at particularly high risk for heat-related illness (HRI). Various factors, including ambient temperatures, personal protective equipment, work arrangements, physical exertion, and work with heavy equipment may put workers at higher risk for HRI. While extreme heat will impact workers across the world, workers in low- and middle-income countries will be disproportionately affected. Tracking occupational HRI will be critical to informing prevention and mitigation strategies. Renewed investment in these strategies, including workplace heat prevention programs and regulatory standards for indoor and outdoor workers, will be needed. Additional research is needed to evaluate the effectiveness of interventions in order to successfully reduce the risk of HRI in the workplace.


Asunto(s)
Trastornos de Estrés por Calor , Enfermedades Profesionales , Humanos , Trastornos de Estrés por Calor/prevención & control , Trastornos de Estrés por Calor/epidemiología , Enfermedades Profesionales/prevención & control , Enfermedades Profesionales/epidemiología , Enfermedades Profesionales/etiología , Calor Extremo/efectos adversos , Exposición Profesional/efectos adversos , Exposición Profesional/prevención & control , Salud Laboral , Cambio Climático , Factores de Riesgo
3.
Environ Res ; 248: 118315, 2024 May 01.
Artículo en Inglés | MEDLINE | ID: mdl-38301760

RESUMEN

Climate change has led to an increase in high ambient temperatures, causing extreme heat events worldwide. According to the World Meteorological Organization (WMO), July 2023 marked a historic milestone as the Earth reached its hottest recorded temperature, precisely hitting the critical threshold of 1.5 °C set by the Paris Agreement. This distressing development led to a stark warning from the United Nations, signaling the dawn of what they call "an era of global boiling". The increasing global temperatures can result in high heat stress which leads to various physiological and biochemical alterations in the human body. Given that cardiovascular diseases (CVDs) are a leading cause of morbidity and mortality globally, heat events exacerbate this public health issue. While clinical and in-vitro studies have suggested a range of pathophysiological and biochemical mechanisms underlying the body's response to heat stress, the complex nature of organ-system level interactions makes precise investigation challenging. To address this knowledge gap effectively, the use of animal models exposed to acute or chronic heat stress can be invaluable. These models can closely replicate the multifaceted effects observed in humans during heat stress conditions. Despite extensive independent reviews, limited focus has been shed on the high heat-induced cardiovascular complications and their mechanisms, particularly utilizing animal models. Therefore, in this comprehensive review, we highlight the crucial biomarkers altered during heat stress, contributing significantly to various CVDs. We explore potential mechanisms underlying heat-induced cardiovascular dysfunction and damage, delving into various animal models. While traditional rodent models are commonly employed, we also examine less conventional models, including ruminants, broilers, canines, and primates. Furthermore, we delve into various potential therapeutic approaches and preventive measures. These insights hold significant promise for the development of more effective clinical interventions against the effects of heat stress on the human cardiovascular system.


Asunto(s)
Enfermedades Cardiovasculares , Sistema Cardiovascular , Calor Extremo , Trastornos de Estrés por Calor , Humanos , Animales , Perros , Pollos , Calor , Salud Pública , Trastornos de Estrés por Calor/prevención & control
4.
Int Arch Occup Environ Health ; 97(1): 35-43, 2024 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-37947815

RESUMEN

PURPOSE: As climate change accelerates, healthcare workers (HCW) are expected to be more frequently exposed to heat at work. Heat stress can be exacerbated by physical activity and unfavorable working requirements, such as wearing personal protective equipment (PPE). Thus, understanding its potential negative effects on HCW´s health and working performance is becoming crucial. Using wearable sensors, this study investigated the physiological effects of heat stress due to HCW-related activities. METHODS: Eighteen participants performed four experimental sessions in a controlled climatic environment following a standardized protocol. The conditions were (a) 22 °C, (b) 22 °C and PPE, (c) 27 °C and (d) 27 °C and PPE. An ear sensor (body temperature, heart rate) and a skin sensor (skin temperature) were used to record the participants´ physiological parameters. RESULTS: Heat and PPE had a significant effect on the measured physiological parameters. When wearing PPE, the median participants' body temperature was 0.1 °C higher compared to not wearing PPE. At 27 °C, the median body temperature was 0.5 °C higher than at 22 °C. For median skin temperature, wearing PPE resulted in a 0.4 °C increase and higher temperatures in a 1.0 °C increase. An increase in median heart rate was also observed for PPE (+ 2/min) and heat (+ 3/min). CONCLUSION: Long-term health and productivity risks can be further aggravated by the predicted temperature rise due to climate change. Further physiological studies with a well-designed intervention are needed to strengthen the evidence for developing comprehensive policies to protect workers in the healthcare sector.


Asunto(s)
Trastornos de Estrés por Calor , Dispositivos Electrónicos Vestibles , Humanos , Equipo de Protección Personal , Temperatura Cutánea , Temperatura , Personal de Salud , Trastornos de Estrés por Calor/prevención & control
5.
BMC Public Health ; 24(1): 1711, 2024 Jun 26.
Artículo en Inglés | MEDLINE | ID: mdl-38926816

RESUMEN

PURPOSE: Global warming has led to an increase in the number and intensity of extreme heat events, posing a significant threat to the health and safety of workers, especially those working outdoors, as they often have limited access to cooling strategies. The present systematic literature review (a) summarizes the current knowledge on the impacts of climate change on outdoor workers, (b) provides historical background on this issue, (c) explores factors that reduce and increase thermal stress resilience, (d) discusses the heat mitigation strategies, and (e) provides an overview of existing policy and legal frameworks on occupational heat exposure among outdoor workers. MATERIALS AND METHODS: In this systematic review, we searched scientific databases including Scopus (N = 855), Web of Science (N = 828), and PubMed (N = 202). Additionally, we identified relevant studies on climate change and heat-stress control measures through Google Scholar (N = 116) using specific search terms. In total, we monitored 2001 articles pertaining to worker populations (men = 2921; women = 627) in various outdoor climate conditions across 14 countries. After full-text assessment, 55 studies were selected for inclusion, and finally, 29 eligible papers were included for data extraction. RESULTS: Failure to implement effective control strategies for outdoor workers will result in decreased resilience to thermal stress. The findings underscore a lack of awareness regarding certain adaptation strategies and interventions aimed at preventing and enhancing resilience to the impact of climate change on heat stress prevalence among workers in outdoor tropical and subtropical environments. However, attractive alternative solutions from the aspects of economic and ecological sustainability in the overall assessment of heat stress resilience can be referred to acclimatization, shading, optimized clothing properties and planned breaks. CONCLUSION: The integration of climate change adaptation strategies into occupational health programs can enhance occupational heat resilience among outdoor workers. Conducting cost-benefit evaluations of health and safety measures for thermal stress adaptation strategies among outdoor workers is crucial for professionals and policymakers in low- and middle-income tropical and subtropical countries. In this respect, complementary measures targeting hydration, work-rest regimes, ventilated garments, self-pacing, and mechanization can be adopted to protect outdoor workers. Risk management strategies, adaptive measures, heat risk awareness, practical interventions, training programs, and protective policies should be implemented in hot-dry and hot-humid climates to boost the tolerance and resilience of outdoor workers.


Asunto(s)
Cambio Climático , Trastornos de Estrés por Calor , Humanos , Trastornos de Estrés por Calor/prevención & control , Trastornos de Estrés por Calor/epidemiología , Exposición Profesional/prevención & control , Exposición Profesional/efectos adversos , Calor/efectos adversos , Femenino , Masculino
6.
Am J Ind Med ; 67(4): 304-320, 2024 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-38345435

RESUMEN

BACKGROUND: To limit exposures to occupational heat stress, leading occupational health and safety organizations recommend work-rest regimens to prevent core temperature from exceeding 38°C or increasing by ≥1°C. This scoping review aims to map existing knowledge of the effects of work-rest regimens in hot environments and to propose recommendations for future research based on identified gaps. METHODS: We performed a search of 10 databases to retrieve studies focused on work-rest regimens under hot conditions. RESULTS: Forty-nine articles were included, of which 35 were experimental studies. Most studies were conducted in laboratory settings, in North America (71%), on healthy young adults, with 94% of the 642 participants being males. Most studies (66%) employed a protocol duration ≤240 min (222 ± 162 min, range: 37-660) and the time-weighted average wet-bulb globe temperature was 27 ± 4°C (range: 18-34). The work-rest regimens implemented were those proposed by the American Conference of Governmental and Industrial Hygiene (20%), National Institute of Occupational Safety and Health (11%), or the Australian Army (3%). The remaining studies (66%) did not mention how the work-rest regimens were derived. Most studies (89%) focused on physical tasks only. Most studies (94%) reported core temperature, whereas only 22% reported physical and/or mental performance outcomes, respectively. Of the 35 experimental studies included, 77% indicated that core temperature exceeded 38°C. CONCLUSIONS: Although work-rest regimens are widely used, few studies have investigated their physiological effectiveness. These studies were mainly short in duration, involved mostly healthy young males, and rarely considered the effect of work-rest regimens beyond heat strain during physical exertion.


Asunto(s)
Trastornos de Estrés por Calor , Exposición Profesional , Estrés Laboral , Masculino , Adulto Joven , Humanos , Femenino , Calor , Australia , Temperatura Corporal/fisiología , Esfuerzo Físico/fisiología , Trastornos de Estrés por Calor/prevención & control
7.
Am J Ind Med ; 67(6): 556-561, 2024 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-38698682

RESUMEN

BACKGROUND: Occupational heat stress, exacerbated by factors such as climate change and insufficient cooling solutions, endangers the health and productivity of workers, especially in low-resource workplaces. OBJECTIVE: To evaluate the effectiveness of two cooling strategies in reducing physiological strain and productivity of piece-rate workers over a 9-h work shift in a southern Thailand sawmill. METHODS: In a crossover randomized control trial design, 12 (33 ± 7 y; 1.58 ± 0.05 m; 51 ± 9 kg; n = 5 females) medically screened sawmill workers were randomly allocated into three groups comprising an established phase change material vest (VEST), an on-site combination cooling oasis (OASIS) (i.e., hydration, cold towels, fans, water dousing), and no cooling (CON) across 3 consecutive workdays. Physiological strain was measured via core temperature telemetry and heart rate monitoring. Productivity was determined by counting the number of pallets of wood sorted, stacked, and stowed each day. RESULTS: Relative to CON, OASIS lowered core temperature by 0.25°C [95% confidence interval = 0.24, 0.25] and heart rate by 7 bpm [6, 9] bpm, compared to 0.17°C [0.17, 0.18] and 10 [9,12] bpm reductions with VEST. It was inconclusive whether productivity was statistically lower in OASIS compared to CON (mean difference [MD] = 2.5 [-0.2, 5.2]), and was not statistically different between VEST and CON (MD = 1.4 [-1.3, 4.1]). CONCLUSIONS: Both OASIS and VEST were effective in reducing physiological strain compared to no cooling. Their effect on productivity requires further investigation, as even small differences between interventions could lead to meaningful disparities in piece-rate worker earnings over time.


Asunto(s)
Estudios Cruzados , Trastornos de Estrés por Calor , Humanos , Tailandia , Femenino , Adulto , Masculino , Trastornos de Estrés por Calor/prevención & control , Frecuencia Cardíaca/fisiología , Enfermedades Profesionales/prevención & control , Enfermedades Profesionales/etiología , Ropa de Protección , Eficiencia , Calor/efectos adversos , Exposición Profesional/prevención & control , Exposición Profesional/efectos adversos , Adulto Joven
8.
Br J Sports Med ; 58(15): 860-869, 2024 Jul 25.
Artículo en Inglés | MEDLINE | ID: mdl-38950917

RESUMEN

Several International Federations (IFs) employ specific policies to protect athletes' health from the danger of heat. Most policies rely on the measurement of thermal indices such as the Wet Bulb Globe Temperature (WBGT) to estimate the risk of heat-related illness. This review summarises the policies implemented by the 32 IFs of the 45 sports included in the Paris 2024 Olympic Games. It provides details into the venue type, measured parameters, used thermal indices, measurement procedures, mitigation strategies and specifies whether the policy is a recommendation or a requirement. Additionally, a categorisation of sports' heat stress risk is proposed. Among the 15 sports identified as high, very high or extreme risk, one did not have a heat policy, three did not specify any parameter measurement, one relied on water temperature, two on air temperature and relative humidity, seven on WBGT (six measured on-site and one estimated) and one on the Heat Stress Index. However, indices currently used in sports have been developed for soldiers or workers and may not adequately reflect the thermal strain endured by athletes. Notably, they do not account for the athletes' high metabolic heat production and their level of acclimation. It is, therefore, worthwhile listing the relevance of the thermal indices used by IFs to quantify the risk of heat stress, and in the near future, develop an index adapted to the specific needs of athletes.


Asunto(s)
Trastornos de Estrés por Calor , Calor , Deportes , Humanos , Trastornos de Estrés por Calor/prevención & control , Deportes/fisiología , Deportes/clasificación , Calor/efectos adversos , Atletas/clasificación , Paris , Política de Salud
9.
Br J Sports Med ; 58(18): 1044-1051, 2024 Sep 09.
Artículo en Inglés | MEDLINE | ID: mdl-39029949

RESUMEN

OBJECTIVE: To evaluate the efficacy of the Fédération Internationale de Football Association (FIFA) cooling break policy against alternative cooling configurations in attenuating thermal strain during simulated football in the heat. METHODS: 12 males (age: 27±6 years, V̇O2peak: 61±7 mL/kg/min) completed five 90 min intermittent treadmill football match simulations in 40°C and 41% relative humidity (32°C wet-bulb globe temperature) with different cooling configurations: regular match without cooling breaks (REG), 3 min breaks without cooling (BRKno-cool), 3 min breaks with cooling (BRKcool: current FIFA policy; chilled fluid ingestion and ice towel across neck and shoulders), 5 min extended half-time without cooling breaks (ExtHTonly) and 3 min cooling breaks with 5 min ExtHT (ExtHTcool). Rectal temperature (Tre), heart rate, whole-body sweat rate (WBSR) and rating of perceived exertion (RPE) were recorded. Data are presented as mean (95% CIs). RESULTS: Final Tre was lower in BRKno-cool (0.20°C (0.01, 0.39), p=0.038), BRKcool (0.39°C (0.21, 0.57), p<0.001) and ExtHTcool (0.40°C (0.22, 0.58), p<0.001) than REG (39.1°C (38.8, 39.3)). Mean Tre was lower in ExtHTcool (38.2°C (38.0, 38.4)) than BRKcool (38.3°C (38.1, 38.5), p=0.018), BRKno-cool and ExtHTonly (38.4°C (38.2, 38.6), p<0.001) and REG (38.5°C (38.3, 38.7), p<0.001). Mean heart rate was lower during BRKcool (6 beats/min (4, 7), p<0.001) and ExtHTcool (7 beats/min (6, 8), p<0.001) compared with REG. WBSR was comparable across trials (p≥0.07) and RPE was attenuated during BRKcool (0.4 (0.1, 0.7), p=0.004) and ExtHTcool (0.5 (0.2, 0.7), p=0.002), compared with REG. CONCLUSION: BRKcool and ExtHTcool attenuated thermal, cardiovascular and perceptual strain during a simulated football match in the heat. Additional strategies may be required in field settings or under harsher conditions.


Asunto(s)
Frecuencia Cardíaca , Calor , Fútbol , Sudoración , Humanos , Masculino , Adulto , Frecuencia Cardíaca/fisiología , Sudoración/fisiología , Fútbol/fisiología , Fútbol/lesiones , Adulto Joven , Regulación de la Temperatura Corporal/fisiología , Temperatura Corporal/fisiología , Prueba de Esfuerzo , Esfuerzo Físico/fisiología , Trastornos de Estrés por Calor/prevención & control , Frío
10.
Int J Biometeorol ; 68(7): 1451-1474, 2024 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-38664286

RESUMEN

In Indian cities where streets are the only affordable outdoor public space, pedestrians are always exposed to extreme heat related health risk. However, it's a challenge to reduce heat stress in existing streets characterized by asymmetrical urban configuration. Integrating vegetation without reconstituting the original orientation and geometry is one of the feasible ways to alleviate stress. Therefore, current study focuses to analyse the heat stress reduction potential of urban greenery strategy in asymmetrical urban configuration from spatiotemporal perspective. It initiates with the selection of commercial streets in extreme hot climate with an on-site measurement of its climatic and morphological attributes. Furthermore, it leads to the classification and prioritizing of street's sections linked to hot-spots determined by varied sky view factor and asymmetrical aspect ratio. Finally, an Envi-Met model with iterated scenarios at the building and street levels is developed, incorporating three strategies (trees, grass, green-walls). The impact of heat related health risk is quantified using a thermal index Universal Thermal Climate Index along with air temperature and mean radiant temperature. The results suggested that due to asymmetricity a fixed strategy would not be applicable across the street. The highest reduction was observed by trees in asymmetrical sections while lowest was recorded by green-wall. However, it would be worthwhile to adopt green-wall along with dense tree's (leaf area density, 0.3) in order to reduce the heat stress in deeper sections. The evidence-based integration of Urban greenery can assist planners and designers in mitigating extreme heat stress in similar complex urban environment.


Asunto(s)
Ciudades , Árboles , India , Modelos Teóricos , Calor , Poaceae , Humanos , Planificación de Ciudades , Trastornos de Estrés por Calor/prevención & control , Clima Tropical
11.
J Sports Sci ; 42(16): 1491-1511, 2024 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-39262133

RESUMEN

This review examined the effect of acute heat mitigation strategies on physiological strain and exercise performance in females exercising in the heat. Three databases were searched for original research with an acute heat mitigation (intervention) and control strategy in active females and reporting core temperature, heart rate and/or aerobic exercise performance/capacity with ≥ 24°C wet bulb globe temperature. Hedges' g effect sizes were calculated to evaluate outcomes. Thirteen studies (n = 118) were included. Most studies that applied an acute heat mitigation strategy to females did not reduce thermal (9/10) or cardiovascular (6/6) strain or improve exercise performance/capacity (8/10). The most effective strategies for attenuating thermal strain were pre-cooling with ice-slurry (effect size = -2.2 [95% CI, -3.2, -1.1]) and ice-vests (-1.9 [-2.7, -1.1]), and pre- and per-cooling with an ice-vest (-1.8 [-2.9, -0.7]). Only pre-cooling with an ice-vest improved running performance (-1.8 [-2.9, -0.7]; ~0.43 min) whilst sodium hyperhydration improved cycling capacity at 70% V O2peak (0.8 [0.0, 1.6]; ~20.1 min). There is currently limited research on acute heat mitigation strategies in females, so the evidence for the efficacy is scarce. Some studies show beneficial effects with ice-slurry, ice-vests and sodium hyperhydration, which can guide future research to support female exercise performance in the heat.


Asunto(s)
Rendimiento Atlético , Temperatura Corporal , Ejercicio Físico , Frecuencia Cardíaca , Calor , Humanos , Frecuencia Cardíaca/fisiología , Femenino , Rendimiento Atlético/fisiología , Ejercicio Físico/fisiología , Temperatura Corporal/fisiología , Hielo , Regulación de la Temperatura Corporal/fisiología , Carrera/fisiología , Trastornos de Estrés por Calor/prevención & control , Trastornos de Estrés por Calor/fisiopatología
12.
Sensors (Basel) ; 24(18)2024 Sep 11.
Artículo en Inglés | MEDLINE | ID: mdl-39338635

RESUMEN

Heat stress impacts ruminant livestock production on varied levels in this alarming climate breakdown scenario. The drastic effects of the global climate change-associated heat stress in ruminant livestock demands constructive evaluation of animal performance bordering on effective monitoring systems. In this climate-smart digital age, adoption of advanced and developing Artificial Intelligence (AI) technologies is gaining traction for efficient heat stress management. AI has widely penetrated the climate sensitive ruminant livestock sector due to its promising and plausible scope in assessing production risks and the climate resilience of ruminant livestock. Significant improvement has been achieved alongside the adoption of novel AI algorithms to evaluate the performance of ruminant livestock. These AI-powered tools have the robustness and competence to expand the evaluation of animal performance and help in minimising the production losses associated with heat stress in ruminant livestock. Advanced heat stress management through automated monitoring of heat stress in ruminant livestock based on behaviour, physiology and animal health responses have been widely accepted due to the evolution of technologies like machine learning (ML), neural networks and deep learning (DL). The AI-enabled tools involving automated data collection, pre-processing, data wrangling, development of appropriate algorithms, and deployment of models assist the livestock producers in decision-making based on real-time monitoring and act as early-stage warning systems to forecast disease dynamics based on prediction models. Due to the convincing performance, precision, and accuracy of AI models, the climate-smart livestock production imbibes AI technologies for scaled use in the successful reducing of heat stress in ruminant livestock, thereby ensuring sustainable livestock production and safeguarding the global economy.


Asunto(s)
Inteligencia Artificial , Trastornos de Estrés por Calor , Ganado , Rumiantes , Animales , Ganado/fisiología , Rumiantes/fisiología , Trastornos de Estrés por Calor/veterinaria , Trastornos de Estrés por Calor/prevención & control , Algoritmos , Aprendizaje Automático , Redes Neurales de la Computación , Cambio Climático
13.
J Therm Biol ; 119: 103798, 2024 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-38310809

RESUMEN

Strategies to alleviate heat stress on live performance - dry matter intake (DMI), average daily gain (ADG), and feed conversion efficiency (FCE) - and on physiological parameters - respiratory rate (RR) and panting score (PS) - of feedlot-finished cattle were evaluated by systematic review-meta-analysis. Using the PICO framework were identified 3813 records, with 31 publications and 6729 cattle being considered in the meta-analysis (MA). The comparison most reported was sun vs. shade (n = 24 publications), followed by shade vs. shade (area per animal and effectivity in reduce solar load) (n = 7 publications) and sun vs. sprinkling (n = 4 publications). Cattle with access to shade with total reduction in solar load improved ADG (p = 0.008) and FCE (p = 0.024), and reduced RR (p < 0.001) compared to unshaded animals. Cattle with access to shade with a height between 3 and 4 m increased ADG (p < 0.001), tended to improve FCE (p = 0.054), and reduced RR (p < 0.001) compared to unshaded animals. An area of shade from 2 to 4 m2/animal increased ADG (p = 0.002), and higher than 4 m2/animal reduced RR (p < 0.001) compared to unshaded animals. Animals that received sprinkling volume below 1 L/animal/min improved ADG (p = 0.008) compared to unshaded animals. Cattle with access to shade with a high area per animal improved DMI (p = 0.023) and ADG (p < 0.001) compared to animals with a low area. In univariate meta-regression, it was observed that the variables significantly (P < 0.05) influencing DMI were THI category; influencing ADG were cattle gender, THI category, and coat color; influencing FCE were cattle age and hemisphere; and influencing RR were country, THI category and climate. Performance and physiological parameters of feedlot-finished cattle under heat stress depend on animal and environmental characteristics.


Asunto(s)
Clima , Trastornos de Estrés por Calor , Bovinos , Animales , Respuesta al Choque Térmico , Frecuencia Respiratoria , Trastornos de Estrés por Calor/prevención & control , Trastornos de Estrés por Calor/veterinaria , Luz Solar , Alimentación Animal/análisis , Dieta/veterinaria
14.
J Therm Biol ; 123: 103905, 2024 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-38941825

RESUMEN

Heat stress poses a significant challenge to sheep farming in arid and semi-arid regions, impacting growth performance, health, and physiological responses. While sheep have innate mechanisms to manage heat stress, prolonged exposure impairs their performance and health. This study evaluated the influence of varying doses of Curcumin Nano-Micelle (CNM) on heat-stressed fattening lambs in northeastern Iran over three months, examining the relationship between CNM doses and growth performance, feeding behavior, physiological responses, immune function, and antioxidant status. Thirty-two crossbred male lambs were included in a completely randomized design with four treatments and eight replications. The experimental treatments were as follows: 1) CTRL: No dietary inclusion of CNM, (control group); 2) T20: Dietary inclusion of 20 mg of CNM per head per day; 3) T40: Dietary inclusion of 40 mg of CNM per head per day; and 4) T80: Dietary inclusion of 80 mg of CNM per head per day. The results revealed that dietary supplementation with 20 and 40 mg of CNM significantly improved live body weight, weight gain, average daily gain (ADG), and feed conversion ratio (FCR) compared to the control treatment. Regression analysis demonstrated quadratic models between growth performance parameters and the Temperature-Humidity Index (THI), indicating a correlation between CNM doses and the animals' responses to heat stress. Regarding eating behavior, CNM doses of 40 and 80 mg/day significantly reduced eating time while increasing ruminating time. Blood analysis indicated significant reductions in glucose levels across all treatments, with T40 significantly reducing both cholesterol and triglyceride (TG) levels. Additionally, CNM supplementation decreased serum malondialdehyde (MDA) levels and increased superoxide dismutase (SOD) and glutathione peroxidase (GPx) activities, indicating enhanced antioxidant status. Physiological responses were influenced by CNM, notably reducing rectal temperature (RT), skin temperature (ST), respiration rate (RR), while pulse rate (PR) increased across various time intervals, particularly in the T80 group. This study demonstrates that CNM supplementation can enhance performance, physiological responses, and antioxidant status in heat-stressed fattening lambs, highlighting its potential to mitigate heat stress effects in sheep farming.


Asunto(s)
Cambio Climático , Curcumina , Suplementos Dietéticos , Respuesta al Choque Térmico , Animales , Masculino , Curcumina/farmacología , Curcumina/administración & dosificación , Respuesta al Choque Térmico/efectos de los fármacos , Ovinos/fisiología , Micelas , Trastornos de Estrés por Calor/veterinaria , Trastornos de Estrés por Calor/prevención & control , Trastornos de Estrés por Calor/tratamiento farmacológico , Humedad , Alimentación Animal/análisis , Antioxidantes
15.
Can Fam Physician ; 70(9): 546-550, 2024 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-39271209

RESUMEN

OBJECTIVE: To describe heat-related illness and provide approaches for treatment in family practice. SOURCES OF INFORMATION: The MeSH terms heat-related illness and primary care were searched in PubMed. Clinical trials, practice reviews, and systematic reviews were included in this review. Reference lists were reviewed for additional articles. MAIN MESSAGE: Extreme heat events are increasing in frequency due to climate change and can directly result in heat exhaustion, heat stroke, or death. Exposure to extreme heat also exacerbates underlying health conditions. Patients may be at increased risk of heat-related illness because of underlying sensitivity to heat, increased exposure to heat, or barriers to resources. CONCLUSION: Family physicians can help prevent heat-related illness by identifying and counselling patients who are at increased risk and by advocating for interventions that reduce the chance of heat-related illness.


Asunto(s)
Medicina Familiar y Comunitaria , Trastornos de Estrés por Calor , Humanos , Trastornos de Estrés por Calor/prevención & control , Trastornos de Estrés por Calor/terapia , Medicina Familiar y Comunitaria/métodos , Atención Primaria de Salud , Calor/efectos adversos , Cambio Climático , Golpe de Calor/prevención & control , Golpe de Calor/terapia , Golpe de Calor/etiología
16.
Wilderness Environ Med ; 35(1_suppl): 112S-127S, 2024 03.
Artículo en Inglés | MEDLINE | ID: mdl-38425235

RESUMEN

The Wilderness Medical Society (WMS) convened an expert panel in 2011 to develop a set of evidence-based guidelines for the recognition, prevention, and treatment of heat illness. The current panel retained 5 original members and welcomed 2 new members, all of whom collaborated remotely to provide an updated review of the classifications, pathophysiology, evidence-based guidelines for planning and preventive measures, and recommendations for field- and hospital-based therapeutic management of heat illness. These recommendations are graded based on the quality of supporting evidence and the balance between the benefits and risks or burdens for each modality. This is an updated version of the WMS clinical practice guidelines for the prevention and treatment of heat illness published in Wilderness & Environmental Medicine. 2019;30(4):S33-S46.


Asunto(s)
Trastornos de Estrés por Calor , Medicina Silvestre , Humanos , Medicina Ambiental , Trastornos de Estrés por Calor/prevención & control , Sociedades Médicas
17.
J Occup Environ Hyg ; 21(1): 58-67, 2024 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-37830911

RESUMEN

Many oil and gas extraction (OGE) activities occur in high-heat environments, resulting in a significant risk of heat-related illness among outdoor workers in this industry. This report highlights cases of occupational heat-related illness that resulted in death and identifies common risk factors for heat-related fatalities and hospitalizations among OGE workers. Two databases maintained by the National Institute for Occupational Safety and Health (NIOSH) and the Occupational Safety and Health Administration (OSHA) were reviewed to identify heat-related fatalities, hospitalizations, and associated risk factors among OGE workers. Nine fatalities and associated risk factors were identified during 2014-2019 from NIOSH's Fatalities in Oil and Gas Extraction (FOG) Database. Risk factors identified included those commonly associated with heat-related fatalities: new workers not acclimatized to heat, inadequate heat stress training, and underlying hypertension or cardiovascular disease. Of particular note, substance use was identified as a significant risk factor as more than half of the fatalities included a positive postmortem test for amphetamines or methamphetamines. Fifty heat-related hospitalizations were identified from OSHA's Severe Injury Report Database during January 2015-May 2021. Heat stress has been and will continue to be an important cause of fatality and adverse health effects in OGE as hot outdoor working conditions become more common and extreme. More emphasis on heat stress training, acclimatization regimens, medical screening, and implementation of workplace-supportive recovery programs may reduce heat-related fatalities and injuries in this industry.


Asunto(s)
Trastornos de Estrés por Calor , Salud Laboral , Estados Unidos/epidemiología , Humanos , Trastornos de Estrés por Calor/prevención & control , Factores de Riesgo , Lugar de Trabajo , Industrias
18.
J Occup Environ Hyg ; 21(2): 97-107, 2024 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-37801404

RESUMEN

Given rising temperatures, globally, heat exposures and catastrophic heat illnesses are a major concern in laborer and industrial sectors. The purpose of this study was to evaluate the perceptions of females laboring in the heat regarding challenges and barriers encountered in their respective industries while working in the heat. A consensual qualitative research (CQR) design was employed to gain information related to participant occupational and job characteristics, feelings while working in the heat, adjustments made by employers when they work in the heat, and their experience working in the heat specific to their identified sex. Females were eligible to participate if they were currently employed in an environment that required them to work in the heat. Twelve females participated in a single, 45-60 min one-on-one semi-structured interview. Participants reported working in the manufacturing, agriculture, tourism, and railroad industries. Upon completion of data analysis, one primary theme was identified: heat stress mitigation strategies, which were further broken down into two subthemes of formal strategies provided by the employer and informal strategies driven by the employees. Participants indicated there was a lack of heat stress prevention strategies implemented by their employers, which resulted in employees creating their own strategies to protect themselves and their coworkers from heat stress. Results indicated there are limited heat stress prevention strategies that are provided in industries that include females working in the heat. Unique considerations should be made to protect this population from the dangers of heat stress and must go beyond workers protecting themselves.


Asunto(s)
Trastornos de Estrés por Calor , Industrias , Humanos , Femenino , Investigación Cualitativa , Trastornos de Estrés por Calor/prevención & control , Trastornos de Estrés por Calor/epidemiología , Temperatura , Agricultura
19.
J Occup Environ Hyg ; 21(8): 591-601, 2024 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-39008819

RESUMEN

Marching band (MB) artists are subject to exertional heat illnesses (EHIs) similar to other active groups like laborers and athletes. Yet, they are an understudied population with no evidence-based heat safety guidelines. Presented here is a case study of the 233rd annual Bristol, RI Independence Day Parade in 2018 that resulted in over 50 EHIs, including 25 from the Saint Anthony Village marching band (MB) from suburban Minneapolis, MN. This research aims to identify the contributing factors that led to the large number of EHIs, as well as guide ensuring the safety of MB artists in future events. A human heat balance model in conjunction with local weather data was used to simulate heat stress on MB artists. Three modeling scenarios were used to isolate the roles of clothing (band uniform vs. t-shirt and shorts), weather (July 4, 2018 vs. 30-year climatology), and metabolic rate (slow, moderate, and brisk marching pacing) on heat stress. The results identify several key factors that increased heat stress. The meteorological conditions were unusually hot, humid, and sunny for Bristol, resulting in reduced cooling from evaporation and convection, and increased radiant heating. Behavioral factors also affect heat stress. The full marching band uniforms reduced evaporative cooling by 50% and the activity levels of marching 4 km over several hours without breaks resulted in conditions that were uncompensable. Finally, it is speculated that a lack of acclimatization for participants from cooler regions may have exacerbated heat-related impacts. These findings highlight several recommendations for MB directors and race organizers, including the use of summer uniforms for anticipated hot conditions, and advance parade planning that includes providing shade/hydration before and after the parade for participants, considering cooler routes that reduce radiant heating and preparing for anticipated heat-related health impacts appropriate for anticipated hot conditions.


Asunto(s)
Trastornos de Estrés por Calor , Calor , Humanos , Trastornos de Estrés por Calor/prevención & control , Masculino , Tiempo (Meteorología) , Adulto , Ropa de Protección/normas
20.
J Occup Environ Hyg ; 21(6): 409-422, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38718416

RESUMEN

With climate change fueling more frequent and intense periods of hot weather, heat stress management programs are becoming increasingly important for protecting the health and safety of workers in the Canadian mining industry. While the inclusion of heat-mitigation measures such as those provided by the American College of Governmental Industrial Hygienists (ACGIH) Threshold Limit Values (TLVs) are commonly employed by industry, there is a need to develop more comprehensive industry-specific measures for heat stress prevention and management. To better understand current heat management practices and identify opportunities for improvement, an exploratory survey of 51 employees responsible for health and safety at underground mining (n = 35), and surface operations (n = 16) (e.g., open-pit mining, milling, smelting, and exploration site) was conducted in Canada. The respondents answered 50 questions related to workplace heat stress management, including descriptors of the workplace environment, perceived heat stress hazard, administration of heat stress management programming, heat stress emergency procedures, environmental monitoring strategies, and knowledge of mining-specific regulations related to heat stress. Twenty-four managers (47%) reported that heat-related illnesses led to restricted duty or lost time claims at their site, with a median of 5 [IQR: 2-10, max: 30] reportable heat-related illnesses occurring per site annually. Many also felt that heat-related illnesses are under-reported by their workforce (n = 36, 71%). Most sites reported established heat stress management programs to prevent heat illness (n = 43, 84%), typically based on the TLVs (n = 38, 75%). Although some organizations do conduct pre-task evaluations for heat stress (n = 30, 59%), more than half do not conduct post-job evaluations (n = 28, 55%) or pre-employment screening for heat stress vulnerability (n = 3, 6%). While our findings indicate that the health and safety managers recognize the hazard posed by heat and have stated practices to help address the hazard, we also observed inconsistencies in heat stress management programming across the sample. Developing and adopting a standard heat stress management and reporting system would be an important step toward protecting workers from existing and emerging threats from extreme heat and climate change.


Asunto(s)
Trastornos de Estrés por Calor , Minería , Humanos , Canadá , Trastornos de Estrés por Calor/prevención & control , Encuestas y Cuestionarios , Exposición Profesional , Adulto , Masculino , Calor , Enfermedades Profesionales/prevención & control , Enfermedades Profesionales/epidemiología , Monitoreo del Ambiente/métodos , Lugar de Trabajo , Femenino , Persona de Mediana Edad , Salud Laboral
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