British scientists have issued a stark warning following an alarming new study of the heatwave gripping India's Thar Desert region, where temperatures have soared to 47°C. The team from the University of Cambridge and the UK Met Office has documented what they describe as a 'collapse of diurnal temperature variation' in the city of Churu, Rajasthan. Data from the study shows that, for the first time in recorded history, night-time temperatures have failed to drop below 35°C for consecutive weeks, while daytime peaks have erased the traditional boundaries of morning and evening.
'Mornings and nights no longer exist in the way we understand them,' said Dr. Meera Patel, the lead author. 'At 47°C, the cycle of day and night becomes irrelevant to the human body.
' The research, published in Nature Climate Change, analysed satellite thermal imagery and ground station data from 2010 to 2025. It reveals that the number of 'tropical nights' (where minimum temperatures exceed 25°C) has increased by 300% since 2010. In June 2024, Churu recorded a minimum temperature of 38.
9°C, the highest ever measured in India. 'What we are seeing is a fundamentally different physical environment,' said co-author Professor James Whitaker. 'The heat capacity of the atmosphere has increased to the point where radiative cooling is no longer efficient.
The desert surface acts like a storage heater, re-radiating heat all night.' The health implications are severe. The Indian government has reported 900 heat-related deaths since April 2025, but the true figure is likely higher.
'Prolonged exposure to such extremes without nocturnal relief leads to cumulative physiological stress,' Dr. Patel explained. 'Kidneys fail.
Hearts give out. The body cannot repair itself.' The study warns that if global carbon emissions continue on their current trajectory, such conditions could become the norm across 30% of South Asia by 2050.
As the planet's energy imbalance deepens, the simple rhythms of day and night are being erased. This is not a future problem. It is happening now.
