India, April 13 -- In the summer of 2024, Uttar Pradesh did not just face a heatwave - it endured the longest stretch of extreme heat India had recorded since 2010. Temperatures across the state's plains breached 40degC for an entire month. Across India, more than 44,000 cases of heatstroke were reported, and independent monitors documented hundreds of heat-related deaths that official tallies chose not to count. Uttar Pradesh, home to over 240 million people, is among the ten states with the highest aggregate heat risk in India. Cities such as Kanpur, Varanasi, and Prayagraj - once classified as dry-heat zones - now record humidity levels that compound thermal stress far beyond what temperature readings alone convey.

The science of heat...