'Fight fire with fire': why eating chilli helps cool you down on a hot day

• 20 tongue-tingling chilli recipes

Daydreaming about ice-cream, air-conditioning or cold beer on a hot day? Make room in your fantasy for a bowl of chilli-doused noodles, spicy jungle curry or brick-red sambal.

The burning mouth and whole-body sweats that chilli can bring on aren't usually considered desirable. But when the mercury rises, those sensations are just what the doctor ordered. They indicate that your body's "internal air conditioning system" is working perfectly.

That's how University of Tasmania food scientist Dr Rajaraman Eri describes the physical response to capsaicin, the component in chilli that produces all of those tingling and sometimes uncomfortable feelings that people either love or hate. Throw a hot day into the mix and responses become even more polarised.

"A meal without chilli, regardless of the weather, is not a meal worth eating," says Palisa Anderson, a Thai-Australian farmer and restaurateur who runs five Chat Thai restaurants in Sydney and Boon Luck Farm in northern NSW. It doesn't matter how humid it gets on the farm, Anderson will happily eat 10-chilli stir-fries.

In many cultures, especially in tropical climates, spicy food is sought out for its ability to make the eater sweat. As it evaporates, the sweat cools down the body.

A meal without chilli ... is not a meal worth eating.

Palisa Anderson

"In Sydney, I'd always complain that my mum would make hot food in the middle of summer," says Lana chef Alex Wong. But after visiting South-east Asia and eating at street stalls, with no air conditioning, he realised sweating is the only relief from the heat. "It doesn't feel good at the time, but after it does."

When you eat chilli, your tongue hasn't actually been burned, but your brain thinks it has so it kickstarts a cooling process that involves, yes, sweating.

However, at Indonesian restaurant Makan in Melbourne's CBD, not everyone was happy that the staff meal on a recent hot day featured chilli-heavy dishes including fried chicken with a bruising sambal belacan.

"One person was like, 'It's hot guys. Why do you want to eat this?'" says co-owner Gracia Seger, a chilli fiend whose grandmother and mother believed chilli helped generate an appetite in hot weather, something she agrees with.

Eri says academic studies have shown that eating chilli regularly can burn kilojoules and stimulate appetite, which might be why people turn to it when they feel too hot to eat. That's Keita Abe's theory, founder of Chaco Ramen in Sydney, who suggests a chilli-coriander ramen to his customers on hot days.

Melbourne chef Aiven Lee, who cooks at Yum Sing House, says that "spicy" excites the tongue more than the other flavours. "I think it's the first thing your tongue tastes."

Jung Eun Chae is the owner of Melbourne's tiny Korean tasting menu restaurant Chae. "There is a Korean saying, 'yi yul chi yul', roughly translated as 'fight fire with fire'," she says.

Chae adds that in traditional Chinese medicine, which she studies, it's believed that cold food in hot weather is bad for digestion and weakens the body's qi, or overall vitality. Eating warming foods can boost your immune system and blood circulation.

If you're still shaking your head, it could be that your genetics make you extra sensitive to chilli. But research shows that you can build your tolerance.

Malaysian-born Boon Low, who owns Do Dee Paidang restaurants in Melbourne, says he didn't eat much chilli until he met his Thai wife. "I think my wife, and now me, have a chilli addiction."

When it's too much, though, you can reach for a few proven remedies. Eri recommends dairy, which is not only cold but also contains fat, which can dissolve capsaicin, the element responsible for chilli's burn.

Cow's milk also has a particular protein that can stop chilli molecules binding to the receptors that tell your mouth it's on fire. Cue yoghurt-based sauces, a glass of milk or mango lassi.

Raw vegetables and fruit, such as cucumber or wax jambu, are Anderson's chosen neutraliser. "Within Thai food, even in the spiciest dishes there's a lot of fruit or some cucumber that's like a foil for the chilli."

Platters of fruit and vegetables are common in Indonesia, too, and are called lalap. Then there's sticky or steamed rice, which many people swear by, but could just give your mouth a moment of relief between bites.

Sydney's hottest dishes

Yellow crab curry, Chat Thai

Palisa Anderson says you'll feel this not just because of the type of chilli used, but the heavy-hitting combo of aromatics and herbs that carry the spice note. Don't be fooled by the coconut milk either. "The high oil content makes the spice linger longer," she says.

Locations in Sydney CBD, Chatswood and Neutral Bay.

Korean fire chicken, Red Pepper

Alex Wong says he could only handle two pieces of this ultra-hot chicken made with gochujang and a little something extra.

4A Lyons Street, Strathfield.

Tom yum soup, Do Dee Paidang

Sydneysiders have been daring themselves to order the super nova (level seven) noodle soup, featuring seven scoops of house chilli powder, for nearly a decade. How high will you go?

9/37 Ultimo Road, Haymarket.

Prawn curry, Lankan Filling Station

One of hottest curries at this leading Sri Lankan eatery, it's the mix of paprika, cardamom, cumin and chilli, roasted long and hard, that combine for a knock-out punch.

58 Riley Street, Darlinghurst.

Kanom jeen tai pla, Caysorn

A southern Thai specialty, this curry noodle soup is heavy on the sour notes, which will make your mouth pucker while it's reeling from the chilli burn. Pass the sliced cucumbers.

106-108A Quay Street, Level 1, Prince Centre Building, Haymarket.

Melbourne's hottest dishes

Tom yum soup, Do Dee Paidang

Owner Boon Low says that beyond level three – the lava – the signature noodle soup loses its balance. That's what you can tell your friends, anyway.

Basement, 353 Little Collins Street, Melbourne.

Cumin lamb skewers, Dainty Sichuan Food

They may not look as angry as the dishes showered in dried chilli, but these skewers pack a double-whammy of spice, thanks to a liberal dousing in cumin.

Locations in South Yarra, Box Hill and Melbourne CBD.

Evil chicken wings, Hot Chicken Project

The most hardcore heat at this Nashville-inspired chicken shop is the "evil". That is, unless you want to go off-menu.

Locations in Geelong and Anglesea.

Tobanjan ramen, Ikkoryu Fukuoka Ramen

This bowl is described as "stomach-twisting" by chilli-lover Boon Low of Do Dee Paidang thanks to its use of Sichuan's favourite chilli paste, doubanjiang. Whether that's good or bad depends how nuts you are for chilli.

23 Russell Street, Melbourne.

Sichuan hot and sour hotpot, Dragon Hot Pot

Yum Sing House chef Aiven Lee says this is one of his go-tos when it's hot. "The hot and numbing quality with a bit of black vinegar acidity brings everything together."

Various locations including Caulfield East, Carlton and Chadstone.