Heat Stress Study Launched in Tamil Nadu and Karnataka to Assess Health Impact and Develop Early Warning System

A comprehensive study has been initiated in Tamil Nadu and Karnataka to evaluate the impact of heat stress on physical and mental health, and to develop a personalised heat-impact metric tool for individuals, homes, and communities.

The M.S. Swaminathan Research Foundation (MSSRF) is leading the project in collaboration with the state governments, SCARF, the Indian Institute of Science in Bengaluru, and ICMR institutions including the National Institute of Traditional Medicine in Belagavi and the National Institute of Epidemiology in Chennai.

“We are looking at getting a granular understanding of the impact of heat on human health in an effort to chart out what different departments need to do,” said MSSRF chairperson Soumya Swaminathan. The project will also assess the preparedness of health systems—from primary to tertiary—to handle heat stress among the population.

The study sites in Tamil Nadu are Perungudi in Chennai and Poompuhar in Mayiladuthurai, while in Karnataka they are Sirwar in Raichur and Chalakarre in Chitradurga. At each site, 1,200 households have been enrolled for the study.

“For a one-degree rise in environment temperature, what will be the heat stress, we will study this,” explained Mohan Kumar, director of health systems and nutrition at MSSRF. In preparation, two weather systems will be installed at every site to measure environmental temperature, pollution, air quality, and humidity.

A total of 80 residents per site, who are participants in the trial, will receive a digital watch to track surface body temperature. Participants will be interviewed in three phases: beginning this summer, followed by non-summer months, and then another summer.

Participants’ vitals will be monitored periodically, along with salivary cortisol levels to understand the impact of heat stress on each individual. Participants have been categorised into low, medium, and high risk for stress based on age, gender, occupation, type of house, and existing co-morbidities.

“We will also be studying the preparedness of health systems to address heat stress. For this, we are working with the governments of the two states, including local bodies and meteorology offices,” Dr. Kumar said. State-level heat-related morbidity and mortality data will also be factored in.

“The first phase of the study will hopefully generate enough information for us to look at coping strategies and strengthening health systems, find promising solutions to handle the crisis, engineer them, implement them, and then scale up,” he added.

Another goal of the study is to develop an early warning system app, which could be personalised for the wearer’s location. It will gather environmental information and, combined with the individual’s specific circumstances, generate a daily heat risk prediction. This could also be produced at the community level, Dr. Kumar explained.