G10 is a variation of Garolite, and comes in a variety of "grades" (G7, G9, G11, etc) and a variety of types, including high-temp G11 (resistant up to 335 degrees), and ultra high-temp G7 (resistant up to 425 degrees). And it can possess a very high tensile strength, as well as impact resistance. I'm not sure how it reacts to extreme cold though. "Multi-purpose" G10 (commonly used for knife handles) has a maximum heat of 265 degrees.
As already stated, G10, FRN, and similar plastics would be your best bet for handles that can survive "rugged" use, not absorb liquids, and not absorb cold.
If a knife might be exposed to bodily fluids, one might consider a knife that can be completely disassembled for a thorough cleaning.