# Spatiotemporal changes in heat stress exposure in India, 1981-2023

## TL;DR

This study analyzes how heat stress exposure has changed across Indian districts from 1981 to 2023, showing an increase and highlighting public health implications.

## Contribution

The study introduces a district-level spatiotemporal analysis of heat stress exposure in India, revealing caste-based inequalities in occupational exposure.

## Key findings

- Average heat stress exposure duration increased by 3.3% between 1981-1995 and 2011-2023.
- Heat stress exposure varies by time of day, season, and region in India.
- Outdoor occupational heat stress exposure shows caste-based inequality from 2019-2023.

## Abstract

India is amongst the most susceptible regions in the world to extreme heat stress because of climate change. In this study, we present a comprehensive analysis of the spatiotemporal evolution of heat stress exposure (HSE) across India’s districts, which serve as the primary administrative units below the State level. Our analysis covers a long temporal duration (1981-2023) and uses data with high spatial (0.1°) and temporal granularity (hourly). By focusing on the district, we ensure that our findings are relevant for policymakers. We find a 3.3% increase in the average HSE duration across districts when comparing 1981-1995 and 2011-2023. We provide evidence for variation in the evolution of HSE by time of day, time of year, and across regions in India. We also provide estimates of changes in outdoor occupational exposure from 2019-2023. Our research highlights the importance of considering HSE in addition to average temperature changes and has important implications for public health practitioners and policymakers.

The authors quantify the changes in heat stress exposure at the district level in India from 1981-2023 using high resolution spatiotemporal data. Findings also highlight caste-based inequality in outdoor occupational heat stress exposure.