FWIW I use Topstick or Toupee Tape (search for Hairdirect .com for cheap good sticking tape strips) for exceptionally sweaty actors - since toupee tape is typically double sided I then cover the top sticky side with normal transpore. Toupee tape is extremely strong durable tape that can withstand sweat and heavy use applications. It is also hypoallergenic and easy to remove with no residue or solvent needed. A variation of this technique if you don't want to wet up the mic or cable against the skin is to apply the toupee tape square to the face, apply the mic cable to the top sticky side, and then cover that with Transpore - making a sandiwch of toupee tape, cable and transpore tape. As others have said - Tegaderm is also very useful but requires a bit of prep and is also a bit expensive.I am currently working on a production. I have a few actors that are heavy sweaters. And the typical 3M Transpore tape doesn't stick well. Any suggestions on alternatives???