Printed in Great Britain Epidemiology of Heat Illnesses During the Makkah Pilgrimages in Saudi Arabia

A review of the literature shows that our knowledge of the epidemiology of heat illnesses on a global and regional level is still lacking. Until now most of the information has come from the experience of European armies in hot environments. Recently increased interest has been shown following the epidemics of heat illnesses affecting civil communities in the United States. Of great importance and unique for the study of heat illness is the start of the hot cycle of the Makkah Pilgrimage which will continue for the next 15-16 years. Approximately two million people, the majority of whom are at great risk, will be exposed to the extremes of hot weather in May-September. Thousands of heat stroke cases are expected to occur. In this paper the conditions prevailing during the annual Makkah Pilgrimage are described as well as a review of the epidemiological and clinical findings observed by the author during the pilgrimages of 1980/81 when 176 cases and 467 cases of Heat Stroke were seen and treated respectively and a new physiological method of treat-ment of heat stroke which proved very successful in clinical field trials was introduced. Exposure to hot environments may result in a variety of heat illnesses—heat cramps, heat exhaustion and heat stroke. Heat stroke is the least common but the most serious. Epidemics of heat illnesses have afflicted ma