Brace yourself: here's where to find the world's spiciest food

India, Mexico, China and Indonesia are all hot contenders but most agree, if you want to brew up a volcano in your mouth, Thailand is the place.

In particular the Isan cuisine of northeast Thailand is reputedly the world's hottest, where the tongue-torturing dishes include green papaya salad, larb, which is minced meat with a spicy seasoning, and bamboo shoot soup with yanang leaves.

Most diners who experience a full-blooded Isan dish for the first time will leave the table with tears.

The ingredient that causes the burn in most Thai food is the jewel-like bird's eye chilli pepper. On the Scoville scale, which measures the heat factor of chillies, a bird's eye chilli has between 50,000 - 100,000 Scoville units (SHU), about 10 times stronger than the common jalapeno pepper.

Current record holder for the world's hottest chilli is the Dragon's Breath at 2.48 million SHU, higher than military-grade pepper spray.

The active ingredient in chillies is capsaicin which acts on heat-sensing receptors on the tongue.

Capsaicin deters predators, but birds can eat chillies without suffering any ill effects, which works to mutual advantage since birds are the main seed spreaders for chilli plants.