- Indoor temperatures in Chennai homes often exceeded 32 degrees Celsius between 2025-2026
- Some households faced up to 5,800 hours of heat exposure, equal to eight months continuously
- Nighttime temperatures rarely dropped below 31 degrees Celsius even in cooler months
A new study that examined 50 residential units in Chennai's urban neighbourhoods between October 2025 and April 2026 has revealed that the indoor temperatures frequently exceeded 32 degrees Celsius.
The worst-affected households recorded between 5,700 and 5,800 hours of exposure above the 32-degree Celsius threshold, equivalent to eight months of continuous heat, the study has found.
Titled "Nighttime Thermal Stress in Low and Middle Income Housing in India: Linking Indoor Temperatures and Relative Humidity with Perceptions of Comfort", the study was released on Wednesday by Climate Trends, a climate-research organisation based in New Delhi.
Every high-income household in the sample had an air-conditioner and every low-income household had only a ceiling fan.
In a statement, Naveen Puttaswamy, associate professor at the Sri Ramachandra Medical College, Chennai, and co-author of the study, said, "Most people spend the majority of their time indoors, where they face the dual threats of heat stress and poor air quality." "These exposures carry uncertain physiological tradeoffs and add psychological as well as economic strain on individuals and households," he added.
The analysis has found that nighttime (between 8 pm and 6 am) temperatures rarely fell below 31 degrees Celsius even during the cooler months of the study period.
It has also highlighted that relative humidity remained consistently above 75 per cent throughout the nighttime hours, compounding discomfort by limiting the body's ability to cool itself through evaporation.
"The structural characteristics of housing play a decisive role in shaping indoor thermal conditions. Reinforced cement concrete (RCC) used in roofing and walls prolongs indoor heat exposure," the study said.
It noted that even air-conditioning cannot mitigate the baseline heat exposure embedded in the structure itself.
RCC buildings retain heat throughout the 24-hour cycle. With the air-conditioner turned off, the heat makes itself felt again.
(This story has not been edited by NDTV staff and is auto-generated from a syndicated feed.)
