Variations of heat exhaustion rate of pilgrims with environmental conditions during hajj seasons between 2002 and 2018 in Makkah, Saudi Arabia

Abstract

Heat exhaustion (HE) is one of the major concerns for medical service providers, especially in hot weather conditions. Every year pilgrims come to Makkah in Saudi Arabia to perform hajj rites which require a lot of physical effort. Makkah has a very hot climate, especially in the summer. Several cases of HE have been reported among pilgrims. The rate of heat exhaustion (HER) among pilgrims was studied using five climatic factors such as temperature (T), relative humidity (RH), heat index (HI), total solar radiation (TSR) and wind speed (WS) during the Hajj seasons between 2002 and 2018 in Makkah. These factors were measured using data collected by the weather stations owned by The Custodian of the Two Holy Mosques Institute for Hajj and Umrah Research at Umm Al-Qura University in Makkah. There is a roughly 11 days difference between solar and lunar years. Occurring in the 12th lunar month of the Islamic calendar, the Hajj is rotating by about 11 days each year. As a result, it will coincide with each month of the solar calendar in a period of about 32 years. Therefore, the HER values ranged between 0.18 per 105 in the winter of 2005 to 35.97 per 105 in the summer of 2018. Simple and multiple linear regression analysis revealed a very high linear relationship among most climate factors and HER (multiple R (MR) ≥ 79 %, R2 ≥ 63 % and P < 10−4). Seven different equation groups of climate factors were applied to predict HER values and showed a very high correlation (MR ≥ 91 %, R2 ≥ 83 % and P ≤ 0.001). Further studies of HER are needed, especially in terms of medical, environmental, demographic, and social sciences in Makkah.