This is a professional wrestling term for, as the name suggests, generating a response (heat) from the crowd in a cheap fashion.

Common methods for a babyface include mentioning and sucking up to the town they're in, mentioning other babyface wrestlers, escaping submission moves at the last second, and making up ridiculous catchphrases.

Common methods for a heel include insulting the town they're in, making fun of the local sports teams, stalling during a match, preaching conservative values, and interfering in other people's matches.

The "cheap" really doesn't imply that the wrestler is cheating by using these methods, only that these things are done so frequently that the audience is trained to automatically respond to them in the correct fashion.