Oddly enough, setting a man on fire isn’t necessarily a bad thing, on the contrary, it’s actually considered curative.
Although I wasn’t able to learn much about this strange medical procedure, fire treatment is apparently very popular during the winter months, in Chinese traditional hospitals. People believe this will keep them safe from illnesses like the flu and common cold.
The piece of cloth is sprinkled with flammable substance, probably alcohol,then set on fire and put-out with another cloth. It isn’t painful at all, and according to a video I found on Youtube, fire treatment is also a great way to lose weight.