Climate change could make much of South Asia too hot for human survival by the end of this century, have scientists warned.   

They said that if global warming continues at its current rate, blistering temperatures will make parts of India, Pakistan and Bangladesh unlivable by the year 2100; alarming news for the 1.5 billion people living in those areas.

Even today, South Asia is no stranger to deadly heat waves. More than 3000 people there died in the summer of 2015, and scientists warn that it's on track to only get worse as the heat becomes more frequent and intense.

Beyond the temperature making some places too hot to live, researchers say crops will end up failing, meaning increased hunger in one of the poorest and most densely populated areas on the planet, potentially forcing millions of people to migrate.

Countries have already begun taking steps to deal with the heat; Pakistan is working with disaster experts to manage the impact of rising temperatures and India has introduced the region's first early warning system against extreme heatwaves.

But according to researchers, it's the prevention that needs to be urgently addressed, not the cure.