Extreme heat is gripping different parts of the world, breaking records and setting off warnings of the devastating consequences of heatwaves to the planet.

Unprecedented high temperatures are especially hazardous to humans; they leave behind a trail of casualties caused mainly by heatstroke and unpreparedness for intense weather conditions.

The sweltering heat threatens food security and exacerbates natural disasters. It also disrupts economic life and opens the door to more frequent heatwaves in the coming year.

Take a look the deadliest heatwaves the Earth has grappled with.