This is a term used to describe extremely hot temperatures, usually anything above 100 degrees farenheit. In the 80's, Kenny and his band came out with the song "The Heat is On...On the street"
A small piece of information. Derived from the word ken, used often in the scottish language and is synonymous with knowledge.
Person 1: "Hey I don't get this shit. How do you solve this problem?"
Person 2: "I got that one. Give me some kenlets on this assignment and I'll help you w/ that one."