India and Pakistan have experienced their hottest April in 122 years. Temperatures are nearing 50C. Such extreme heat dries up water reservoirs, melts glaciers and damages crops. It’s also deadly. Ian Sample hears from Pakistan reporter Shah Meer Baloch about the situation on the ground, and speaks to Indian heat health expert Abhiyant Tiwari about what such temperatures do to the body and how south Asia is adapting to ever more frequent – and ever more extreme – heatwaves.. Help support our independent journalism at theguardian.com/sciencepod