Extreme Heat Kills Even in Very Hot Cities: Evidence from Nagpur, India.

Background: Although many studies have provided evidence for all-cause mortality attributed to extreme temperature across India, few studies have provided a systematic analysis of the association between all-cause mortality and temperature.

Objective: To estimate the risk associated with heat waves during two major heat waves of Nagpur occurred in 2010 and 2014.

Methods: The association between temperature and mortality was measured using a distributed lag non-linear model (DLNM) and the attributable deaths associated with the heat waves with forward perspective in the DLNM framework.

Results: From the ecological analysis, we found 580 and 306 additional deaths in 2010 and 2014, respectively. Moving average results also gave similar findings. DLNM results showed that the relative risk was 1.5 for the temperature above 45 °C; forward perspective analysis revealed that the attributable deaths during 2010 and 2014 were 505 and 376, respectively. Results from different methods showed that heat waves in different years had variable impacts for various reasons. However, all the results were consistent during 2010 and 2014; there were 30% and 14% extra-mortalities due to heat comparing to non-heat wave years.

Conclusion: We strongly recommend the city Government to implement the action plans based on this research outcome to reduce the risk from the heat wave in future.