"The warm cups contain coffee."
Translation:La varmetaj tasoj enhavas kafon.
i don't think there's exactly defined temperatures. Just a relative order in a range that can be expected from the context. (in this sentence: coffee)
varma = hot (but drinkable), varmeta = warm (body temperature and up a bit)
and along that line: vermega = hot (maybe too hot to drink) and malvarma (under body temperature, but a long way from frozen)
something along those lines.