What does the word heat mean?

Usage examples for heat

  1. Then, while he waited for these to heat, he crawled back into his sleeping bag. – Bobby of the Labrador by Dillon Wallace
  2. It was not only that I had worked myself into a heat for nothing. – The Professor's Mystery by Wells Hastings Brian Hooker
  3. You wonder if he too feels the heat. – On the Heels of De Wet by The Intelligence Officer