A new Oxford University study highlights a sobering climate future: if global average temperatures rise toward **2 °C above pre-industrial levels — a scenario scientists find increasingly likely — nearly 3.8 billion people worldwide could face dangerous levels of extreme heat by 2050. India, with its vast and growing population, ranks among the countries with the highest number of people exposed to these escalating heat risks.

The research, published in Nature Sustainability, also reveals that the share of humanity exposed to life-threatening temperatures could jump from about 23 per cent in 2010 to 41 per cent by mid-century if warming trends continue unchecked. While some nations — especially in Africa and Southeast Asia — face sharp rises in heat exposure, populous countries such as India, Nigeria, Indonesia, Bangladesh, Pakistan and the Philippines will experience the largest absolute numbers of affected people.

The study underlines that significant increases in heat stress occur well before the 2 °C mark, meaning societies must prepare sooner for adaptation and mitigation. Beyond health impacts like heatstroke and dehydration, extreme heat pressures infrastructure, energy systems and labour productivity. Researchers warn that climate planning — from resilient buildings and cooling systems to early warning infrastructures — must accelerate now, even as global efforts to cut emissions continue.