Heat illnesses: a hot topic in the setting of global climate change.

BACKGROUND: Heat illnesses affect a large number of people every year and are becoming an increasing cause of pathology as climate change results in increasing global temperatures. OBJECTIVE: This article will review the physiological responses to heat, as well as the pathophysiological processes that result in heat illnesses. The emphasis will be on providing general practitioners (GPs) with an understanding of how to prevent heat illness in their patients and how to predict who is most at risk. DISCUSSION: Heat illnesses may be thought of as minor or major illnesses, any of which may present to the GP. Consideration must be given to identifying those who need more critical intervention and on when to transfer for higher-level of care.

The impact of heat waves on children's health: a systematic review.

Young children are thought to be particularly sensitive to heat waves, but relatively less research attention has been paid to this field to date. A systematic review was conducted to elucidate the relationship between heat waves and children's health. Literature published up to August 2012 were identified using the following MeSH terms and keywords: "heatwave", "heat wave", "child health", "morbidity", "hospital admission", "emergency department visit", "family practice", "primary health care", "death" and "mortality". Of the 628 publications identified, 12 met the selection criteria. The existing literature does not consistently suggest that mortality among children increases significantly during heat waves, even though infants were associated with more heat-related deaths. Exposure to heat waves in the perinatal period may pose a threat to children's health. Pediatric diseases or conditions associated with heat waves include renal disease, respiratory disease, electrolyte imbalance and fever. Future research should focus on how to develop a consistent definition of a heat wave from a children's health perspective, identifying the best measure of children's exposure to heat waves, exploring sensitive outcome measures to quantify the impact of heat waves on children, evaluating the possible impacts of heat waves on children's birth outcomes, and understanding the differences in vulnerability to heat waves among children of different ages and from different income countries. Projection of the children's disease burden caused by heat waves under climate change scenarios, and development of effective heat wave mitigation and adaptation strategies that incorporate other child protective health measures, are also strongly recommended.

A Bayesian model averaging approach for estimating the relative risk of mortality associated with heat waves in 105 U.S. cities.

Estimating the risks heat waves pose to human health is a critical part of assessing the future impact of climate change. In this article, we propose a flexible class of time series models to estimate the relative risk of mortality associated with heat waves and conduct Bayesian model averaging (BMA) to account for the multiplicity of potential models. Applying these methods to data from 105 U.S. cities for the period 1987-2005, we identify those cities having a high posterior probability of increased mortality risk during heat waves, examine the heterogeneity of the posterior distributions of mortality risk across cities, assess sensitivity of the results to the selection of prior distributions, and compare our BMA results to a model selection approach. Our results show that no single model best predicts risk across the majority of cities, and that for some cities heat-wave risk estimation is sensitive to model choice. Although model averaging leads to posterior distributions with increased variance as compared to statistical inference conditional on a model obtained through model selection, we find that the posterior mean of heat wave mortality risk is robust to accounting for model uncertainty over a broad class of models.

Heat-related illnesses during the 2003 heat wave in an emergency service.

INTRODUCTION: This study describes patients admitted to an urban emergency service in France during the 2003 heat wave. Patients with heat-related illnesses were studied and comparison was made between those who died and survivors. METHODS: A retrospective study of about 760 records concerning 726 patients aged over 65 years admitted during August 2003 to a French emergency department. RESULTS: After review of the medical records, 42 patients had heat-related illnesses. Heat-related illnesses were not diagnosed by the treating physician in any of the patients. The patients were more likely to live in institutional care and used more psychotropic medications. Hyperthermia and acute cognitive impairment were the main reasons for admission to the emergency department. The patients had a higher heart rate and body temperature and more dyspnoea and central nervous system dysfunction than those without heat-related illnesses. Twelve patients (28.6%) with heat-related illnesses died in the emergency unit or after admission to hospital. Temperature, heart rate and plasma creatinine levels were higher in those who died than in survivors with heat-related illnesses. CONCLUSION: Heat-related illnesses are a group of underestimated and underdiagnosed conditions with high morbidity and mortality rates.

[Identifying residential areas with heat-related health risks. Sociodemographic and climate data mapping as a planning tool for targeted prevention strategies]. / Wohngebiete mit hitzeabhängigen Gesundheitsrisiken ermitteln. Soziodemografische und klimatische Kartierung als Planungsinstrument gezielter Prävention.

Prognosticated heat waves in the context of climate change require appropriate strategies to prevent harmful health effects in the population. In a model project within the public health department of the Kassel region, elderly living in areas at risk of over-heating will be identified and advised. The localization of high-risk residential areas was part of the planning process. Through mapping of demographic and microclimate data and the characteristics of the material of the residential buildings, high-risk areas that require preventive measures as a top priority were identified. The prevention of heat-related mortality and morbidity by communal health authorities requires close cooperation with other administrative bodies, especially with town planning departments. Mapping demographic and microclimate data and the characteristics of the material of the residential buildings can facilitate the planning of preventive measures.

Global climate change and human health.

Global climate change is a vexing economic, environmental, and public health problem. Climatologists have documented a rise in global average temperature that is unprecedented since the Industrial Revolution. This temperature change correlates with increasing concentrations of atmospheric carbon dioxide (CO2) and other greenhouse gases, which largely are of human origin. Global climate change is likely to profoundly affect global health. This article summarizes the science of climatology and global climate change caused by human actions and reviews potential health effects.

Unauthorized border crossings and migrant deaths: Arizona, New Mexico, and El Paso, Texas, 2002-2003.

OBJECTIVES: We examined the major causes of and risk factors for death among migrants who died while making unauthorized border crossings into the United States from Mexico. METHODS: Decedents were included in the study if (1) their remains were found between January 1, 2002, and December 31, 2003, in any US county along the 650-mi (1040-km) section of the US-Mexican border from Yuma, Ariz, to El Paso, Tex; (2) their immigration status was unauthorized; and (3) they were believed to have died during transit from Mexico to the United States. Characteristics of the decedents and causes of and risk factors for their deaths were examined. RESULTS: Among the 409 decedents meeting our inclusion criteria, environmental heat exposure (n=250; 61.1%) was the leading cause of death, followed by vehicle crashes (n=33; 8.1%) and drownings (n=24; 5.9%). Male decedents (n= 298; 72.8%) outnumbered female decedents (n = 105; 25.6%) nearly 3 to 1. More than half of the decedents were known to be Mexican nationals (n=235; 57.5%) and were aged 20 to 39 years (n=213; 52.0%); the nationality of 148 (36.2%) decedents was undetermined. CONCLUSIONS: Deaths among migrants making unauthorized crossings of the US-Mexican border are due to causes that are largely preventable. Prevention strategies should target young Mexican men, and focus on preventing them from conceiving plans to cross the border, discouraging them from using dangerous routes as crossing points, and providing search-and-rescue teams to locate lost or injured migrant crossers.

Excess deaths during the August 2003 heat wave in Paris, France.

BACKGROUND: During the August 2003 heat wave in France, almost 15,000 excess deaths were recorded. Paris was severely affected, with an excess death rate of 141%. This study had two aims: to identify individual factors associated with excess deaths during a heat wave in an urban environment and to describe the spatial distribution of deaths within the French capital. METHODS: The study population included all people who died at home between August 1st and 20th, 2003 (N=961). We identified factors associated with excess deaths by comparing the sociodemographic characteristics of the study population with those of people who died at home during the same period in reference years (2000, 2001, 2002) (N=530). Spatial differences were analysed by calculating comparative mortality rates within Paris during August 2003. Mortality ratio was determined to demonstrate temporal variations in mortality between the heat wave period and reference years. RESULTS: The major factors associated with excess death were: age over 75 years (adjusted OR=1.44 (1.10-1.90), being female (adjusted OR=1.43 (1.11-1.83)), not being married (adjusted OR=1.63 (1.23-2.15)), particularly for men. Being a foreigner appeared to be a protective factor for women. Comparative mortality rates by neighbourhood showed a gradient in excess deaths from North-West to South-East. The mortality ratio was 5.44 (5.10-5.79), with very high rates of excess death in the South (12th, 13th, 14th and 15th "arrondissement"). CONCLUSION: The August 2003 heat wave in Paris was associated with both an exceptional increase in mortality rates and changes in the characteristics of those dying and spatial distribution of mortality. Understanding the effects of a heat wave on mortality can probably be improved by an analysis of risk at two levels: individual and contextual.

Heat-related deaths--United States, 1993.

From July 1 through July 13, 1993, the heat wave in the eastern United States has been implicated as the direct cause of or a contributing factor to 84 deaths among persons residing in the Philadelphia area. In Philadelphia County, the medical examiner (ME) lists hyperthermia as a contributing factor leading to death if a decedent is elderly or infirm and was exposed to a hot environment. However, reporting of hyperthermia on a death certificate depends on the criteria of individual MEs or coroners. This article describes three case reports of heat-related deaths in other parts of the United States in 1993, summarizes risk factors for this problem, and reviews measures to prevent heat-related illness.

Heat-related deaths--Philadelphia and United States, 1993-1994.

During June 1994, temperatures across the United States were higher than usual. Since June 13, record high temperatures (above 90 F [32.2 C]) with humidities of 50%-60% have occurred in the northeastern United States (1). During July 1-14, 1993, the eastern United States also experienced a severe heat wave with high temperatures (93 F-101 F [33.9 C-38.3 C]) and high humidity (36%-58%) (2). During July 6-14, 1993, in Philadelphia, medical examiners (MEs) determined 118 deaths were heat-related*. This report describes heat-related deaths that occurred in Philadelphia during 1993 and 1994 and summarizes risk factors for heat-related illness and death.

Heat--related illnesses and deaths-United States, 1994-1995.

Although heat-related illness and death are readily preventable, exposure to extreme temperatures causes at least 240 deaths during years with no heat wave. A heat wave is defined by the National Weather Service as > or = 3 consecutive days of temperatures > or = 90.0 F (> or = 32.2 C). In 1980, 1983, and 1988 (recent years with prolonged heat waves), 1700, 556, and 454 deaths, respectively, were attributed to heat. This report describes four instances of heat-related illness and death that occurred in the United States during 1994 and 1995 and summarizes risk factors for heat-related illness and death.

Heatstroke in psychiatric patients: two cases and a review.

Two fatal cases of heatstroke in psychiatric patients are described. A literature search revealed published reports of heatstroke involving 51 psychiatric patients, 22 of whom died. The mean age of these patients was 44 years; the majority has schizophrenia. Almost all were male and were taking antipsychotic or other drugs with anticholinergic effects. The implications for prevention, recognition, and treatment are discussed.

Fatal heat-related illness in naval cadets in Ecuador.

On 13 April 1982, after a 6 to 7 km training run on an extremely hot and humid day, 20 of 216 cadets at the Ecuadorian Naval Academy in Guayaquil became ill with symptoms of heat-related illness. Four of them suffered heat stroke, and three died. Illness was most highly associated with the amount of exercise performed that day but was significantly more common in first-year cadets than in older cadets. There were no differences in the anthropometric measurements of ill and well subjects. We conclude that heat-related illness can affect conditioned military personnel during routine training in severe weather and make recommendations for prevention.

Acute heat stroke deaths.

Ten cases of death due to heat stroke are described. They were all young men who collapsed during running exercise or route march and died in hospital later. Post-mortem examination was carried out in all cases. Death was due to disseminated intravascular coagulation with widespread microthrombus formation and coagulative necrosis involving many organs. Meteorological studies showed that at the time of the collapse the environmental temperature was higher than average although it may have been in the morning or evening.

Mortality from heat stress in broiler chickens influenced by anticoccidial drugs.

The relationship of anticoccidial drug to heat stress mortality in broilers was studied in a replicated floor-pen experiment during a period of hot weather in Georgia. Overall mortality during the 8-week study averaged 6% in unmedicated and monensin-medicated birds or lasalocid-medicated birds, 10% in arprinocid-medicated birds, and 36% in nicarbazin-medicated birds. Most of the death losses were attributed to heat stress. Maximum death losses coincided with three periods of hot weather, when the birds were 22, 33, or 49 days old. Of 114 dead birds in the nicarbazin treatment, 68 were male and 46 were female.