Climate change is not only increasing temperatures and extreme weather events but it is also putting a silent toll on people’s health by reducing the amount of sleep they get.
Rising nighttime temperatures linked to climate change are causing severe sleep loss across India, with Tamil Nadu having the highest annual sleep loss among all states according to Climate Central.
The report says warmer nights are making it harder for people to fall asleep and stay asleep. Unlike daytime heat, which can usually be escaped through shade or air-conditioned spaces, high nighttime temperatures directly interfere with the body’s natural cooling process, necessary for quality sleep.
The most affected state is Tamil Nadu, which is the most affected by climate change driven heat in terms of the number of people losing more sleep per year due to climate driven heat than any other state in India.
Other states with significant sleep loss include Kerala, Karnataka, Maharashtra, Andhra Pradesh, and Telangana, which suffer from high humidity in addition to hotter temperatures at night, which has added to the discomfort.
Climate Central's findings are based on long-term temperature observations and scientific models that estimate how much of the nighttime warming can be attributed to human induced climate change.
The report explains that excessive nighttime heat disrupts the body’s internal temperature regulation, making it harder to enter deep and restorative sleep cycles.
Health experts say sleep deprivation can have far-reaching consequences. Poor sleep has been associated with heart disease, diabetes, obesity, anxiety, depression, weakened immunity, and diminished productivity in the workplace.
Children, elderly people, outdoor workers, and people without access to cooling facilities are particularly vulnerable.
Urban areas are experiencing an even greater impact because of the “urban heat island” effect. Concrete buildings, roads, and limited green spaces trap heat during the day and release it slowly at night, keeping cities drastically warmer than surrounding rural areas. Rapid urbanisation across India has only made this problem more acute.
The report also expresses concerns about climate inequality. Low-income families frequently don’t have air conditioning or well-insulated homes, leaving them in uncomfortable sleeping conditions during heatwaves. That’s why the burden of climate-related sleep loss falls disproportionately on economically vulnerable communities.
The analysis should be used by governments and city planners to ensure that heat-resilient measures are included in urban development, they say. Extending tree cover, creating more green space, building designs that are more architecturally appropriate to cool, and strengthening heat action plans can help reduce nighttime temperatures.
At the individual level, people are advised to stay hydrated, keep bedrooms well ventilated, use cooling methods when possible, avoid heavy meals before bed, and limit screen time before sleeping to improve sleep quality during hot nights.
With climate change increasing in intensity, its repercussions are extending beyond immediate disasters like floods and heatwaves to the health side of things.
The Climate Central report makes it clear that even basic human needs such as sleep are at risk from global warming and climate change in fact, climate action is no longer only an environmental imperative but also a public health issue.
