#i truly cannot think of a sweatier episode of columbo than troubled waters#the man pours#but who's complaining

How about “An Exercise in Fatality”?  Wore an actual sweatsuit and was visibly sopping. 

This... this sounds like a fetish but it’s just an observation.

an interesting vote!

now while he does perspire a respectable amount in that episode, he really spends only these couple scenes visibly sweating. in troubled waters the heat is palpable and the sweat is like. a motif.

I accept your analysis!