Yu might like setting his mouth on fire, but he's not a proselytising firebrand to his diners. "I might like a lot of chillies but others may not, so you play around, see what the feedback is and adjust. In the early days, dishes here were way more spicy. Despite my grand notions, I still have to please people."

It's the same approach that chef Kris Olbrich has for his jerk chicken served at the new Caribbean bar Rummin' Tings. The West Indian spicy pepper rub is a favourite for those who enjoy their smoked meats with a kick, but Olbrich wants to keep it mellow as he introduces it to locals.

"To be honest, I don't want to blow people's heads off," he says. "I want it to have an attitude, but at a medium spice level. Actually, Southeast Asian food is spicier than Caribbean. I've been surprised that many people request the jerk to be spicier. I think the demand for spicy is increasing."

We've all heard the rationale as to why people enjoy the masochistic fun of ingesting food that burns. It induces sweat that cools down the body in hot weather. Conversely, in winter, what's more warming than a steaming Sichuan hot pot? That fiery zing and punch can supply key vitamins and minerals, act as a pain reliever, help digestion, clear the mind, improve circulation and help with weight loss.

Spicy food also delivers a temporary high, so that burning sensation hurts so good. "Chillies do make you euphoric. It's addictive," Yu says. Olbrich adds: "You can build your tolerance, but it also goes away. I grew up in New York and my dad loves spicy, so I thought I had a high tolerance. Then I moved to Bangkok, and my tolerance was nothing compared to the locals. Then, slowly, my tongue built up resistance. I'm sure now in Hong Kong, my tolerance has decreased some."

But have Hongkongers become more tolerant of hot and spicy food? The debate rages on.

Cantonese cuisine tends to be delicate and subtle - suitable for mellow flavours, not spicy ingredients that overwhelm and dominate a dish. But spicier cuisine such as Sichuan is gaining in popularity. And as foodie hipsterism grows, there is also a trend towards hot fads ranging from Korean kimchi to Mexican salsa.

Chef Will Meyrick, who creates sweat-inducing Balinese/Southeast Asian dishes at Mama San, thinks that while Hong Kong has come a long way, the city's diners are still not very brave.

"Not too much has changed, although I have seen the expansion of different styles of cuisine popping up," he says. "Still, there do not seem to be so many Southeast Asian restaurants, even compared to eight years ago." That was when Meyrick launched his first Hong Kong eatery, Lotus.

"It's a milder palate compared to Thailand and even the rest of Asia. I believe it's very much the Cantonese influence. Cantonese originally was never too spicy or hot. It is surprising that Hong Kong, a cultural epicentre of food, doesn't have a high tolerance for spicy dishes. "Traditional Cantonese doesn't use many chillies, but in the last 10 years more mainland chefs from Yunnan, Sichuan and other regions have set up restaurants, and they are more liberal with their chillies. They become popular and bring something different to the table. Chilli oils and peppercorns are very aromatic."

Hutong's refined northern Chinese flavours have been impressing customers for 10 years atop One Peking in Kowloon, with chef Ng Kam-wai keeping its mala pepper dishes humming at a consistent scorch.

"A lot of our dishes remain fiery and authentically northern Chinese - just how we like it," Ng says.

"I think now that guests are understanding the balance involved in a beautifully spicy dish, they seem to like the level of spice we provide. It is complex. Apart from fiery flavours, we use elements of sweet and sour, vinegars and salty to balance a spicy dish."

Certain cuisines are unfairly stigmatised, striking fear in heat-adverse diners. Bombay Dreams serves primarily northern Indian food, which uses a lot of spices but isn't necessarily spicy. But that hasn't stopped customers from constantly wanting milder flavours.

"People connect Indian with spicy, and they always ask how hot the food is," says the restaurant's manager, Ashutosh Bisht. "About half of them want dishes that are not too spicy, so it's a consideration in planning the menu. But there are also people who always want it hotter. So now we've created some amuse-bouche to test customers. After they try them, we know how much spice they can handle and recommend dishes."

Olbrich thinks people shouldn't be afraid of the heat and should try to embrace a little bit as part of the whole gastronomic experience. "It's an extra element, extra flavour. You don't need to burn your tongue off, but people who refuse anything spicy are missing out."

Ultimately for chefs, spiciness is a flavour, not a macho contest. You don't eat sushi with a thick layer of wasabi or munch on scotch bonnet peppers for pleasure. They are tools to tingle the taste buds, not weapons of mouth incineration.

"Personally, if a dish is meant to be lip-smacking hot, I do expect it to be fiery," Meyrick says. "On the other hand, if the dish is meant to have no chilli, then I enjoy the other flavours and won't add more chillies to make it hotter. Chilli is just one in the wide range of spices and should never be over or underestimated, over or underused."