the show which featured him recounting the entire story and his thought processes over the 14 days, but I recall him describing battling hypothermia and the eerie warm feeling it gives you. He didn't seem stupid or panicked. So, although I can't remember the exact reason he didn't melt the snow, I don't think it was that he didn't know he could.
Anyway, yes to survival kits. A jug of water couldn't hurt.