Health Warmth, moisture, and friction lead to chafing, an uncomfortable form of skin irritation that makes your skin feel like it’s on fire. Though it commonly affects the inner thighs, this can happen all over the body, especially in places that sweat and rub against clothes like underarms, breasts, and feet. Mild chafing can sting, burn, or look like a rash, explains Melanie Palm, MD, a board-certified dermatologist at Art of Skin MD in San Diego, California.