The increasing frequency of fatal heat waves in different parts of the world raises major concerns about the health of populations in the context of climate change [1]. A heat wave is defined as a series of consecutive days with extremely hot weather both during the day and at night, compared to local seasonal norms [2]. This phenomenon has adverse effects on human health, particularly heat-related illnesses. These include heat cramps, syncope, exhaustion, and heat stroke [3]. Heat stroke is a life-threatening medical emergency. Classical heat stroke is the most severe clinical form of illness resulting from prolonged exposure to heat, defined by central hyperthermia above 40˚C, in the absence of infection, and associated with central nervous system disorders such as convulsions, mental confusion or comatose [2][4][5].

In developed countries, the incidence of heat stroke observed in some studies varies from one country to another. Indeed, during heat waves in the United States, the incidence varies from 17.6 to 26.5 per 100,000 people [6]. In Canada, studies have shown that summer temperatures are associated with an increase in morbidity [7]. France experienced a heat wave during the summer of 2003, responsible for extreme temperatures with dramatic consequences on morbidity and mortality, with an excess of 14,800 deaths attributed to the heat wave [8][9]. In Saudi Arabia, the incidence varies from 22 to 250 cases per 100,000 people depending on the pilgrimage seasons, with an estimated mortality rate of 50% [10].

Data on the incidence of classic heatstroke are scarce in sub-Saharan Africa, as the disease is not often recognized. And the limited studies available address the effects of climate change on human health [11][12]. Burkina Faso is particularly exposed to periods of increasingly frequent and severe heat waves and heat waves [13]. Specifically, in major cities where death statistics are better monitored, there has been an increase in the number of deaths, especially during the month of April 2024. Clinicians who make the observation are almost unanimous that these are mainly people over 50 years [14]. To date, there has been no study on the medical aspects of the topic in Burkina Faso, which prompted us to carry out this study. The main objective was to describe the epidemiological, clinical, therapeutic and prognostic profile of patients hospitalized for heat stroke in the Medical Emergency Department of the Bogodogo University Hospital Center.

Our study aimed to investigate the epidemiological profile of patients hospitalized for heatstroke in the Medical Emergency Department of Bogodogo University Hospital Center and identify associated factors. However, the results of our study must be interpreted considering certain methodological limitations notably: the underestimation or overestimation of events (Out-of-hospital deaths are not accounted for, which may lead to an incomplete assessment of mortality) and the Selection bias (excluding incomplete or missing records can introduce bias if these records systematically differ from complete ones). This limits the representativeness of the sample; In addition, the retrospective nature limits the ability to make causal relationships.

During our study period, we recorded 974 admissions to the department, including 167 cases of heat stroke, a proportion of 17.15%, which constituted an epidemic since it was the first time that we observed this phenomenon in our country. In the literature, the incidences of studies carried out in America, Europa and Asia vary between 10% - 30% [6][8][10][15][16]. The occurrence of this epidemic is linked to climate change, which leads to increasingly frequent heat waves [1][9].

The average age in our study was nearly 73 years, indicating that the population most vulnerable is mainly composed of elderly people. Indeed, aging leads to a reduction in thermoregulatory capacity, a decreased response to heat, and an increased prevalence of comorbidities, which increases vulnerability to heat stroke [2][5][17]. The advanced age observed in our study aligns with most other research findings [8][17][18].

The high frequency of cardiovascular diseases (50.9%) and diabetes (13.77%) highlights that these pathologies increase susceptibility to heat stroke. These diseases can impair the ability to regulate heat and increase the severity of complications. The use of antihypertensives, neuroleptics or other medications can have side effects related to thermoregulation or increase dehydration. Other authors also report that comorbidities are risk factors for the occurrence of heat stroke [3]-[5][10].

The mean core temperature in our study was 42.2˚C with extremes from 39.8˚C to 42.6˚C. Temperatures below 40˚C could be explained by the peripheral treatment received before admission. Adam BRUT in his study, “diagnosis and management of heat stroke” said that it was important to include such cases in the diagnosis of heatstroke [3]. We found that temperature is a prognostic factor when exceeding 41˚C (p < 0.05). In humans, a temperature above 41˚C - 42˚C for a period of 45 minutes to 8 hours is considered to result in cellular damage and constitutes a critical temperature [5][18][19]. Management must therefore be immediate to reduce body temperature. The majority of patients presented almost systematic dehydration (98.2%,) which reflected hydro electrolytic disorders including hypernatremia (92 cases or 55%). Convulsions and alterations in the state of consciousness with Glasgow score less than 10 (97 cases 58%) reflected the neurodynamic severity, increasing the risk of major complications. These findings are consistent with European and American studies conducted during heatwaves in 2007 and 1998 [3][5].

The average hospital stay was 2.55 days, with a mortality rate of 86 cases (51.15%). This excess mortality highlighted the severity of heat stroke during this epidemic in our context. This is due to the lack of knowledge of this pathology by the population and healthcare providers. The prognostic factors included renal failure (57 cases or 34%,), multi-organ failure (39 cases or 23%,), cardiovascular shock (26 cases or 15%). This mortality is consistent with those observed in studies conducted in developed countries which vary between 30% and 65% [6][8][15][16].

Data comparing according to the mortality show that age, core temperature, respiratory distress, tachycardia, and altered state of consciousness were associated factors in the death group. However, in the multivariate logistic regression, only initial vital signs were statistically significant. Aurélia Marfisi and colleagues also found in their 2008 study that central hyperthermia on admission was a prognostic factor for heat stroke [8][17].

This was the first epidemic of heat stroke in our context. Our study shows that heat stroke primarily affects older people. Clinical features were dominated by neurological signs, dehydration, and respiratory distress. Multiple organ failure and shock constituted the majority of complications, which conducted a high mortality. Treatment consisted mainly of rehydration and cooling, extremely high core temperatures (>41˚C) were associated with poorer prognosis and higher mortality rates. Rapid and appropriate management is crucial to improve the prognosis. Given the retrospective nature of the study, identifying factors associated with survival was a limitation.