Diagnosing and managing heat exhaustion: insights from a systematic review of cases in the desert climate of Mecca

Heat exhaustion (HE) is a common, yet obscure, heat-related illness that affects millions of people yearly and its burden is projected to rise due to climate change. A comprehensive literature synthesis is lacking despite previous studies on various HE aspects. This systematic review aims to fill this gap by identifying and synthesizing available evidence on the risk factors, symptoms, biomarkers, treatment options, and outcomes for HE. The review focused on HE during the Muslim (Hajj) pilgrimage where the condition is endemic. We conducted a structured search of MEDLINE/PubMed, Embase, Web of Science Core Collection, SCOPUS, and CINAHL databases. We summarized the data from eligible studies and synthesized them in narrative form using pooled descriptive statistics. Ten studies were included between 1980 and 2019, reporting over 1,194 HE cases. HE cases presented with elevated core temperature (up to 40 degrees C) andmainly affected older males from the Middle East and North Africa region, with overweight individuals at a higher risk. Clinical symptoms included hyperventilation, fatigue, dizziness, headaches, nausea, and vomiting, but not central nervous system disturbances. HE was associated with cardiac stress, and with water, electrolyte, and acid-base alterations. Cooling and hydration therapy were the primary management strategies, leading to a low mortality rate (pooled case fatality rate=0.11 % [95 % CI: 0.01, 0.3]). Most cases recovered within a few hours without complications. HE is associated with cardiac stress and changes in homeostasis, leading to distinct clinical symptoms. Early diagnosis and treatment of HE are crucial in reducing the risk of complications and mortality. The review provides insights into the pathophysiology and outcomes of HE, adding to the scarce literature on the subject. Prospero registration number: CRD42022325759.

Automated summary

Heat exhaustion is a common but often overlooked heat-related illness, affecting millions of people annually and expected to increase due to climate change. This systematic review aims to fill the gap in the literature by synthesizing available evidence on risk factors, symptoms, biomarkers, treatment options, and outcomes for heat exhaustion. The review focuses on heat exhaustion during the Muslim pilgrimage, where it is endemic. Ten studies were included, reporting over 1,194 cases of heat exhaustion. Elevated core temperature and cardiac stress were common features, and cooling and hydration therapy were effective in managing the condition, resulting in a low mortality rate. Early diagnosis and treatment are crucial in reducing complications and mortality.