What they need to make is a heat shrink condom. It should be loose enough to easily put on at 20-25 degrees and a snug fit at 36.6 degrees. In warm countries, or for added macho-ness, keep it in the fridge or run it under cold water (in the packet) before use.
Hypothetical technical silliness
Date: 2002-09-12 04:16 pm (UTC):-)
Pavlos