Understanding parent and caregiver perceptions of paediatric vehicular hyperthermia: implications for public health messaging from a pilot study.

BACKGROUND: Paediatric vehicular hyperthermia (PVH) is the leading cause of non-crash vehicle-related death of children in the USA. Public health messaging is an important mitigation strategy, yet it is difficult to assess the effectiveness in reducing deaths. Here, we seek to better understand parent/caregiver perceptions on PVH to guide risk communication. METHODS: This pilot study focuses on a subset of participants (n=127) from a national survey, comprising parents/caregivers who met specific eligibility criteria (ie, those who both drive and have children ≤5 years of age). Survey participants answered questions about the perceived severity of forgetting a child in a hot car and their susceptibility to doing so, with responses recorded on a 7-point Likert scale (1=strongly disagree and 7=strongly agree). RESULTS: Our findings indicate that while on average (mean responses of 2.45 and 2.49) parents/caregivers did not consider themselves susceptible, they did acknowledge the severity (mean response of 6.12) of leaving a child unattended in a vehicle. The results suggest that because of this low perceived susceptibility, parents/caregivers are less likely to take protective actions aimed at preventing these incidents from happening. CONCLUSIONS: Public health messaging on PVH should emphasise the universal risk to all parents/caregivers so as to foster greater awareness of the need to take protective actions. Furthermore, engaging secondary audiences such as teachers and healthcare professionals can amplify this message and offer concrete behavioural interventions to mitigate the risk of forgetting a child in a car.

Parade safety and planning: A heat balance case study of marching band artists.

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.

IOC consensus statement on recommendations and regulations for sport events in the heat.

This document presents the recommendations developed by the IOC Medical and Scientific Commission and several international federations (IF) on the protection of athletes competing in the heat. It is based on a working group, meetings, field experience and a Delphi process. The first section presents recommendations for event organisers to monitor environmental conditions before and during an event; to provide sufficient ice, shading and cooling; and to work with the IF to remove regulatory and logistical limitations. The second section summarises recommendations that are directly associated with athletes' behaviours, which include the role and methods for heat acclimation; the management of hydration; and adaptation to the warm-up and clothing. The third section explains the specific medical management of exertional heat stroke (EHS) from the field of play triage to the prehospital management in a dedicated heat deck, complementing the usual medical services. The fourth section provides an example for developing an environmental heat risk analysis for sport competitions across all IFs. In summary, while EHS is one of the leading life-threatening conditions for athletes, it is preventable and treatable with the proper risk mitigation and medical response. The protection of athletes competing in the heat involves the close cooperation of the local organising committee, the national and international federations, the athletes and their entourages and the medical team.

Variations of wet-bulb globe temperature across high school athletics in South Carolina.

The purpose was to describe wet bulb globe temperature (WBGT) throughout a high school fall athletic season (August to November) after a state-wide mandate requiring schools to use a WBGT-guided activity modification table with categories (AMTC). A cross-sectional research design utilized 30 South Carolina high schools. The independent variables were region (upstate, midlands, and coastal), sport (football, tennis, cross-country), month, start times (7-10 am, 10 am-3 pm, 3-6 pm, and 6-9 pm), and event type (practice, competition). Dependent variables were event frequency, average WBGT, and AMTC. Practice WBGT was 78.7 ± 8.2 °F (range: 34.7 to 99.0 °F). A significant difference for WBGT across month (F6, 904.7 = 385.07, P < 0.001) existed, with early September hotter than all other months (84.8 °F ± 3.8, P < 0.001). Every month had practices in each AMTC, until early November. Most events (64.6%, n = 1986) did not change AMTC; however, 9.1% (n = 281) changed to a hotter category. The 10 am-3 pm start time was significantly hotter than all other time frames (83.0 °F ± 7.2, P < 0.05). Tennis experienced hotter practices (79.9 °F ± 6.9) than football (78.4 °F ± 8.5; P < 0.001) and cross country (78.2 °F ± 8.8, P < 0.001). Schools in the Midlands experienced hotter practices (80.1 °F ± 7.8) than upstate (P < 0.001) and coastal schools (P = 0.005). Competition WBGT was significantly cooler than practices (72.3 ± 10.5 °F, t = 12.04, P < 0.001) and differed across sports (F2, 20.78 = 18.39, P < .001). Both cross-country (P = 0.003) and tennis (P < 0.001) were hotter than football. Schools should continuously monitor WBGT throughout practices and until November to optimize AMTC use. Risk mitigation strategies are needed for sports other than football to decrease the risk of exertional heat illnesses.

Prehospital management of exertional heat stroke at sports competitions: International Olympic Committee Adverse Weather Impact Expert Working Group for the Olympic Games Tokyo 2020.

OBJECTIVES: This document aimed to summarise the key components of exertional heat stroke (EHS) prehospital management. METHODS: Members of the International Olympic Committee Adverse Weather Impact Expert Working Group for the Olympic Games Tokyo 2020 summarised the current best practice regarding the EHS prehospital management. RESULTS: Sports competitions that are scheduled under high environmental heat stress or those that include events with high metabolic demands should implement and adopt policy and procedures for EHS prehospital management. The basic principles of EHS prehospital care are: early recognition, early diagnosis, rapid, on-site cooling and advanced clinical care. In order to achieve these principles, medical organisers must establish an area called the heat deck within or adjacent to the main medical tent that is optimised for EHS diagnosis, treatment and monitoring. Once admitted to the heat deck, the rectal temperature of the athlete with suspected EHS is assessed to confirm an elevated core body temperature. After EHS is diagnosed, the athlete must be cooled on-site until the rectal temperature is below 39°C. While cooling the athlete, medical providers are recommended to conduct a blood analysis to rule out exercise-associated hyponatraemia or hypoglycaemia, provided that this can be safely performed without interrupting cooling. The athlete is transported to advanced care for a full medical evaluation only after the treatment has been provided on-site. CONCLUSIONS: A coordination of care among all medical stakeholders at the sports venue, during transport, and at the hospital is warranted to ensure effective management is provided to the EHS athlete.

Exertional heat illnesses in marching band artists: a case series.

Marching band (MB) artists frequently spend many hours engaged in outdoor physical activity. Anecdotal evidence and small studies have indicated that MB artists do experience heat-related health problems. Yet, unlike athletes, military personnel, or workers, there is very little research on heat-related hazards among this unique population. Here, we seek to understand the incidence and circumstances under which exertional heat illnesses (EHIs) occur among MB artists over a 31-year period (1990-2020) across the USA. Using an on-line news dataset, we identified 34 separate events and at least 393 total EHIs. Heat syncope (~ 55%) and heat exhaustion (~ 44%) comprised the majority of EHIs, although a small number of exertional heat stroke cases were also reported. EHIs were reported in all types of MB activities with ~ 32% during rehearsal, ~ 29% during parades, ~ 21% during competition, and ~ 15% during a performance. Also, the vast majority of events occurred with high school (~ 88%) marching bands. Finally, EHIs overwhelmingly occurred when the weather was unusually hot by local conditions. In light of these findings, we emphasize the need for MB specific heat polices that incorporate weather-based activity modification, acclimatization, education about EHIs, and access to on-site medical professionals.

Regional differences in exertional heat illness rates among Georgia USA high school football players.

Many high school associations in recent years are developing policies to improve player safety regarding exertional heat illnesses (EHIs). A question is whether states with diverse climates need multiple sets of guidelines with different activity modification thresholds. We examine this question in the state of Georgia, which has a diverse climate. Our study leverages a multi-year dataset of exertional heat illnesses (EHIs) among high school football players to test the hypothesis that EHI rates under similar wet bulb globe temperatures (WBGTs) will be greater among athletes in the cooler, northern region versus warmer, southern region of the state. The focus of this study is on a 3-year period (2012-2014) when uniform heat safety polices, including acclimatization and activity modification guidelines, were implemented across the state. Results show that athletes in the northern region acclimatize to cooler conditions. Almost 68% of practices have WBGTs < 27.8 °C (82 °F) compared to the southern region where athletes receive many times the exposures to hotter WBGTs in the 27.8-30.5 °C and 30.6-32.2 °C categories. In the post-acclimatization period, we observed statistically significantly (p < .05) greater EHI rates among athletes in the northern region of the state, even when controlling for meteorological conditions. Our findings suggest that differential acclimatization between football players in the northern and southern regions of the state is impacting EHI rates and that regional heat safety guidelines may be needed in Georgia and other states with similarly diverse climates.

Comparison of WBGTs over Different Surfaces within an Athletic Complex.

Many athletic governing bodies are adopting on-site measurement of the wet-bulb globe temperature (WBGT) as part of their heat safety policies. It is well known, however, that microclimatic conditions can vary over different surface types and a question is whether more than one WBGT sensor is needed to accurately capture local environmental conditions. Our study collected matched WBGT data over three commonly used athletic surfaces (grass, artificial turf, and hardcourt tennis) across an athletic complex on the campus of the University of Georgia in Athens, GA. Data were collected every 10 min from 9:00 a.m. to 6:00 p.m. over a four-day period during July 2019. Results indicate that there is no difference in WBGT among the three surfaces, even when considered over morning, midday, and afternoon practice periods. We did observe microclimatic differences in dry-bulb temperature and dewpoint temperature among the sites. Greater dry-bulb and lower dewpoint temperatures occurred over the tennis and artificial turf surfaces compared with the grass field because of reduced evapotranspiration and increase convective transfers of sensible heat over these surfaces. The lack of difference in WBGT among the surfaces is attributed to the counterbalancing influences of the different components that comprise the index. We conclude that, in a humid, subtropical climate over well-watered grass, there is no difference in WBGT among the three athletic surfaces and that, under these circumstances, a single monitoring site can provide representative WBGTs for nearby athletic surfaces.

Heat-Related Illnesses Transported by United States Emergency Medical Services.

Background and objectives: Heat-related illness (HRI) can have significant morbidity and mortality consequences. Research has predominately focused on HRI in the emergency department, yet health care leading up to hospital arrival can impact patient outcomes. Therefore, the purpose of this study was to describe HRI in the prehospital setting. Materials and Methods: A descriptive epidemiological design was utilized using data from the National Emergency Medical Services (EMS) Information System for the 2017-2018 calendar years. Variables of interest in this study were: patient demographics (age, gender, race), US census division, urbanicity, dispatch timestamp, incident disposition, primary provider impression, and regional temperatures. Results: There were 34,814 HRIs reported. The majority of patients were white (n = 10,878, 55.6%), males (n = 21,818, 62.7%), and in the 25 to 64 age group (n = 18,489, 53.1%). Most HRIs occurred in the South Atlantic US census division (n = 11,732, 33.7%), during the summer (n = 23,873, 68.6%), and in urban areas (n = 27,541, 83.5%). The hottest regions were East South Central, West South Central, and South Atlantic, with peak summer temperatures in excess of 30.0 °C. In the spring and summer, most regions had near normal temperatures within 0.5 °C of the long-term mean. EMS dispatch was called for an HRI predominately between the hours of 11:00 a.m.-6:59 p.m. (n = 26,344, 75.7%), with the majority (27,601, 79.3%) of HRIs considered heat exhaustion and requiring the patient to be treated and transported (n = 24,531, 70.5%). Conclusions: All age groups experienced HRI but particularly those 25 to 64 years old. Targeted education to increase public awareness of HRI in this age group may be needed. Region temperature most likely explains why certain divisions of the US have higher HRI frequency. Afternoons in the summer are when EMS agencies should be prepared for HRI activations. EMS units in high HRI frequency US divisions may need to carry additional treatment interventions for all HRI types.

Activity modification in heat: critical assessment of guidelines across athletic, occupational, and military settings in the USA.

Exertional heat illness (EHI) risk is a serious concern among athletes, laborers, and warfighters. US Governing organizations have established various activity modification guidelines (AMGs) and other risk mitigation plans to help ensure the health and safety of their workers. The extent of metabolic heat production and heat gain that ensue from their work are the core reasons for EHI in the aforementioned population. Therefore, the major focus of AMGs in all settings is to modulate the work intensity and duration with additional modification in adjustable extrinsic risk factors (e.g., clothing, equipment) and intrinsic risk factors (e.g., heat acclimatization, fitness, hydration status). Future studies should continue to integrate more physiological (e.g., valid body fluid balance, internal body temperature) and biometeorological factors (e.g., cumulative heat stress) to the existing heat risk assessment models to reduce the assumptions and limitations in them. Future interagency collaboration to advance heat mitigation plans among physically active population is desired to maximize the existing resources and data to facilitate advancement in AMGs for environmental heat.

Assessment of the Australian Bureau of Meteorology wet bulb globe temperature model using weather station data.

Exertional heat illnesses affect thousands of athletes each year and are a leading cause of death in sports. The wet bulb globe temperature (WBGT) is widely used as a heat stress metric in athletics for adjusting activities. The WBGT can be measured on-site with portable sensors, but instrument cost may provide a barrier for usage. Modeling WBGT from weather station data, then, presents an affordable option. Our study compares two WBGT models of varying levels of sophistication: the Australian Bureau of Meteorology (ABM) model which uses only temperature and humidity as inputs and a physically based model by Liljegren that incorporates temperature, humidity, wind speed, and solar radiation in determining WBGT outputs. The setting for the study is 19 University of Georgia Weather Network stations selected from across the state of Georgia, USA, over a 6-year period (2008-2014) during late summer and early fall months. Results show that the ABM model's performance relative to the Liljegren model varies based on time of day and weather conditions. WBGTs from the ABM model are most similar to those from the Liljegren model during midday when the assumption of moderately high sun most frequently occurs. We observed increasingly large positive biases with the ABM model both earlier and later in the day during periods with lower solar radiation. Even during midday, large (≥ 3 °C) underestimates may occur during low wind conditions and overestimates during periods with high cloud cover. Such differences can lead to inaccurate activity modification and pose dangers for athletes either by underestimating heat-related hazards or by imposing an opportunity cost if practice activities are limited by overestimating the heat hazard.

Evaluation of individual and area-level factors as modifiers of the association between warm-season temperature and pediatric asthma morbidity in Atlanta, GA.

INTRODUCTION: Previous studies have found associations between respiratory morbidity and high temperatures; however, few studies have explored associations in potentially sensitive sub-populations. METHODS: We evaluated individual and area-level factors as modifiers of the association between warm-season (May-Sept.) temperature and pediatric respiratory morbidity in Atlanta. Emergency department (ED) visit data were obtained for children, 5-18 years old, with primary diagnoses of asthma or respiratory disease (diagnoses of upper respiratory infections, bronchiolitis, pneumonia, chronic obstructive pulmonary disease, asthma, or wheeze) in 20-county Atlanta during 1993-2012. Daily maximum temperature (Tmax) was acquired from the automated surface observing station at Atlanta Hartsfield International Airport. Poisson generalized linear models were used to estimate rate ratios (RR) between daily Tmax and asthma or respiratory disease ED visits, controlling for time and meteorology. Tmax effects were estimated for single-day lags of 0-6 days, for 3-, 5-, and 7-day moving averages and modeled with cubic terms to allow for non-linear relationships. Effect modification by individual factors (sex, race, insurance status) and area-level socioeconomic status (SES; ZIP code levels of poverty, education, and the neighborhood deprivation index) was examined via stratification. RESULTS: Estimated RRs for Tmax and pediatric asthma ED visits were positive and significant for lag days 1-5, with the strongest single day association observed on lag day 2 (RR=1.06, 95% CI: 1.03, 1.09) for a change in Tmax from 27°C to 32°C (25th to 75th percentile). For the moving average exposure periods, associations increased as moving average periods increased. We observed stronger RRs between Tmax and asthma among males compared to females, non-white children compared to white children, children with private insurance compared to children with Medicaid, and among children living in high compared to low SES areas. Associations between Tmax and respiratory disease ED visits were weak and non-significant (p-value>0.05). CONCLUSIONS: Results suggest socio-demographic factors (race/ethnicity, insurance status, and area-level SES) may confer vulnerability to temperature-related pediatric asthma morbidity. Our findings of weaker associations among children with Medicaid compared to other health insurance types and among children living in low compared to high SES areas run counter to our belief that children from disadvantaged households or ZIP codes would be more vulnerable to the respiratory effects of temperature. The potential reasons for these unexpected results are explored in the discussion.

Children forgotten in hot cars: a mental models approach for improving public health messaging.

INTRODUCTION: On average, in the USA, 37 young children die every year due to vehicular heatstroke. Additionally, over half of these incidents occur when a parent/caregiver forgets a child in a vehicle. While various governmental and child safety advocacy groups have worked to raise awareness about these tragedies, rigorous studies have yet to be conducted that examine the current understanding and effectiveness of this public health messaging. METHODS: This study will employ a mental models approach in order to identify differences that exist between experts' and parents'/caregivers' knowledge and beliefs surrounding the topic of children forgotten in hot cars. We interviewed a diverse set of 25 parents/caregivers and seven experts in order to construct and explore these mental models. RESULTS: A comparative analysis was conducted, and three key differences were observed between these mental models. Unlike the experts, the parents/caregivers in the study emphasised perceived lifestyle factors (eg, low-income parent) as important elements in increasing an individual's likelihood of forgetting a child in a car. Importantly, the parents/caregivers primarily obtained information from news reports, while experts believed public health campaigns would reach more parents/caregivers. Lastly, while experts stressed that this tragedy could happen to anyone, most parents/caregivers failed to acknowledge that they could forget their own child in a car. CONCLUSIONS: To confront this denial, future public health messaging must strive to engage and reach all parents/caregivers. This can be accomplished using a multifaceted messaging strategy that includes personalising core messaging, providing additional resources to media outlets and building rapport between key partners.

American football and fatal exertional heat stroke: a case study of Korey Stringer.

On August 1, 2001, Korey Stringer, a Pro Bowl offensive tackle for the Minnesota Vikings, became the first and to date the only professional American football player to die from exertional heat stroke (EHS). The death helped raise awareness of the dangers of exertional heat illnesses in athletes and prompted the development of heat safety policies at the professional, collegiate, and interscholastic levels. Despite the public awareness of this death, no published study has examined in detail the circumstances surrounding Stringer's fatal EHS. Using the well-documented details of the case, our study shows that Stringer's fatal EHS was the result of a combination of physiological limitations, organizational and treatment failings, and extreme environmental conditions. The COMfort FormulA (COMFA) energy budget model was used to assess the relative importance of several extrinsic factors on Stringer's EHS, including weather conditions, clothing insulation, and activity levels. We found that Stringer's high-intensity training in relation to the oppressive environmental conditions was the most prominent factor in producing dangerous, uncompensable heat stress conditions and that the full football uniform played a smaller role in influencing Stringer's energy budget. The extreme energy budget levels that led to the fatal EHS would have been avoided according to our modeling through a combination of reduced intensity and lower clothing insulation. Finally, a long delay in providing medical treatment made the EHS fatal. These results highlight the importance of modern heat safety guidelines that provide controls on extrinsic factors, such as the adjustment of duration and intensity of training along with protective equipment modifications based on environmental conditions and the presence of an emergency action plan focused on rapid recognition and immediate on-site aggressive cooling of EHS cases.

Warm season temperatures and emergency department visits in Atlanta, Georgia.

PURPOSE: Extreme heat events will likely increase in frequency with climate change. Heat-related health effects are better documented among the elderly than among younger age groups. We assessed associations between warm-season ambient temperature and emergency department (ED) visits across ages in Atlanta during 1993-2012. METHODS: We examined daily counts of ED visits with primary diagnoses of heat illness, fluid/electrolyte imbalances, renal disease, cardiorespiratory diseases, and intestinal infections by age group (0-4, 5-18, 19-64, 65+years) in relation to daily maximum temperature (TMX) using Poisson time series models that included cubic terms for TMX at single-day lags of 0-6 days, controlling for maximum dew-point temperature, time trends, week day, holidays, and hospital participation periods. We estimated rate ratios (RRs) and 95% confidence intervals (CI) for TMX changes from 27°C to 32°C (25th to 75th percentile) and conducted extensive sensitivity analyses. RESULTS: We observed associations between TMX and ED visits for all internal causes, heat illness, fluid/electrolyte imbalances, renal diseases, asthma/wheeze, diabetes, and intestinal infections. Age groups with the strongest observed associations were 65+years for all internal causes [lag 0 RR (CI)=1.022 (1.016-1.028)] and diabetes [lag 0 RR=1.050 (1.008-1.095)]; 19-64 years for fluid/electrolyte imbalances [lag 0 RR=1.170 (1.136-1.205)] and renal disease [lag 1 RR=1.082 (1.065-1.099)]; and 5-18 years for asthma/wheeze [lag 2 RR=1.059 (1.030-1.088)] and intestinal infections [lag 1 RR=1.120 (1.041-1.205)]. CONCLUSIONS: Varying strengths of associations between TMX and ED visits by age suggest that optimal interventions and health-impact projections would account for varying heat health impacts across ages.

Evaluating infant core temperature response in a hot car using a heat balance model.

PURPOSE: Using a 1-year old male infant as the model subject, the objectives of this study were to measure increased body temperature of an infant inside an enclosed vehicle during the work day (8:00 am-4:00 pm) during four seasons and model the time to un-compensable heating, heat stroke [>40 °C (>104 °F)], and critical thermal maximum [>42 °C (>107.6 °F)]. METHODS: A human heat balance model was used to simulate a child's physiological response to extreme heat exposure within an enclosed vehicle. Environmental variables were obtained from the nearest National Weather Service automated surface observing weather station and from an observational vehicular temperature study conducted in Austin, Texas in 2012. RESULTS: In all four seasons, despite differences in starting temperature and solar radiation, the model infant reached heat stroke and demise before 2:00 pm. Time to heat stroke and demise occurred most rapidly in summer, at intermediate durations in fall and spring, and most slowly in the winter. In August, the model infant reached un-compensable heat within 20 min, heat stroke within 105 min, and demise within 125 min. The average rate of heating from un-compensable heat to heat stroke was 1.7 °C/h (3.0 °F/h) and from heat stroke to demise was 4.8 °C/h (8.5 °F/h). CONCLUSIONS: Infants left in vehicles during the workday can reach hazardous thermal thresholds quickly even with mild environmental temperatures. These results provide a seasonal analogue of infant heat stroke time course. Further effort is required to create a universally available forensic tool to predict vehicular hyperthermia time course to demise.

A retrospective analysis of American football hyperthermia deaths in the United States.

Over the period 1980-2009, there were 58 documented hyperthermia deaths of American-style football players in the United States. This study examines the geography, timing, and meteorological conditions present during the onset of hyperthermia, using the most complete dataset available. Deaths are concentrated in the eastern quadrant of the United States and are most common during August. Over half the deaths occurred during morning practices when high humidity levels were common. The athletes were typically large (79% with a body mass index >30) and mostly (86%) played linemen positions. Meteorological conditions were atypically hot and humid by local standards on most days with fatalities. Further, all deaths occurred under conditions defined as high or extreme by the American College of Sports Medicine using the wet bulb globe temperature (WBGT), but under lower threat levels using the heat index (HI). Football-specific thresholds based on clothing (full football uniform, practice uniform, or shorts) were also examined. The thresholds matched well with data from athletes wearing practice uniforms but poorly for those in shorts only. Too few cases of athletes in full pads were available to draw any broad conclusions. We recommend that coaches carefully monitor players, particularly large linemen, early in the pre-season on days with wet bulb globe temperatures that are categorized as high or extreme. Also, as most of the deaths were among young athletes, longer acclimatization periods may be needed.

Weather, geography, and vehicle-related hyperthermia in children.

Vehicle-related hyperthermia is an unfortunate tragedy that leads to the accidental deaths of children each year. This research utilizes the most extensive dataset of child vehicle-related hyperthermia deaths in the United States, including 414 deaths between 1998 and 2008. Deaths follow a seasonal pattern, with a peak in July and no deaths in December or January. Also, deaths occurred over a wide range of temperature and radiation levels and across virtually all regions, although most of them took place across the southern United States. In particular, the Phoenix, Houston, Dallas, and Las Vegas metropolitan areas had the greatest number of deaths. We utilize our vehicle hyperthermia index (vhi) to compare expected deaths versus actual deaths in a metropolitan area, based on the number of children in the area who are under the age of five and on the frequency of hot days in the area. The vhi indicates that the Memphis, West Palm Beach-Boca Raton, and Las Vegas metropolitan areas are the most dangerous places for vehicle-related hyperthermia. We conclude by discussing several recommendations with public health policy implications.