Threshold determination and temperature trends analysis of Indian cities for effective implementation of an early warning system

Abstract

Abstract Extreme heat events (EHEs) have been linked to increased mortality rates, rendering them a valuable research topic in both climate and public health. Early warning systems are highly impactful in prevention and management of heat-related illnesses. We aimed to determine the preliminary maximum temperature thresholds for Nagpur and Rajkot city of India by analyzing the meteorological and mortality data to enable the heat-health response system based on the heat wave disaster risk of a particular state and city. We conducted a trend analysis with daily maximum temperature and all-cause mortality data of Nagpur and Rajkot (2003–2017) cities, also city-specific thresholds evaluated for both cities. There was a significant association between all-cause mortality and extreme heat events and it was more profound when temperatures were above 40.1\xa0°C, but V-shaped relationship of mortality-temperature was noted only for Nagpur city. The dose-response relationship between maximum temperatures and deaths alert thresholds to activate heat health response for red alert set at 46\xa0°C and 44\xa0°C for Nagpur and Rajkot city respectively. This study suggests that determining local thresholds is important for developing and implementing scientific early warning systems to prevent heat-related illnesses.