Consumers' love affair with spicy foods is still going strong.

Since its introduction in 1996, Wendy’s Spicy Chicken Sandwich quickly became a solid fan favorite, even before spicy was hot. As one of the first such offerings in quick service, the sandwich relies on the strength of the spices in the chicken fillet to deliver flavor and heat.

“Since its introduction, the recipe has remained unchanged,” says Liz Geraghty, vice president of brand marketing for the Wendy’s Co. in Dublin, Ohio. “Once people taste the sandwich, they fall under its hot and spicy spell. With its irresistible fiery blend of eight spices and peppers, this original classic has long been Wendy’s top-selling chicken sandwich.”

Recognizing that heat is definitely hot these days, this past summer the company upped the sandwich a couple notches with the limited-edition Jalapeño Fresco Spicy Chicken Sandwich. It featured the same spicy chicken fillet, but with the addition of ghost pepper sauce, cheese, red onion and fresh jalapeños, all sandwiched between a bakery-inspired, toasted red jalapeño bun.

Wendy’s is on track with serving what consumers crave. According to a January 2015 online survey of 1,300 US adults conducted by Kalamazoo, Mich.-based Kalsec, more than half (56 percent) of consumers eat spicy foods at least once a week, with one out of four eating spicy foods more often than a year ago.

“We learned that two out of five consumers think foods taste better with some level of heat, with two-thirds of survey respondents preferring a medium or higher heat level in foods,” says Gary Augustine, executive director of market development at Kalsec. “Although jalapeño remains the preferred chili, it is closely followed by cayenne and chipotle. Habanero, poblano, serrano and ancho are all growing in popularity.”