Green’s Dictionary of Slang

hot pants n.

also hot drawers, warm britches
[hot adj. (1a) + SE pants]

1. [1920s+] (US) strong sexual desire; often as have hot pants for.

2. [1930s+] a sexually eager woman; occas. man.

3. attrib. use of sense 2.

4. [1960s–70s] (US) extreme keenness.

5. [1960s+] a term of address to a sexually eager woman (or one who is seen as such).