Heat

From wikipedia:

1. Negative reactions (such as booing) from fans. When the heat is directed at a heel, this is seen as a good thing, as it means fans are reacting in the desired way. 2. Real-life tension or ill will between two wrestlers, or a wrestler and the promotion.

In The SWS, heat, and similar words, are also used to describe the audience reactions or expectations about a match or a wrestler. For example, a "heated match" means fans are expecting the match to be good or that the wrestlers involved are likely in a feud/rivalry.