The ones that I raise are really good when it's hot.They don't need to be in the cooler.But,when it gets down to under 65 degrees they don't even move around.Then when it's cold outside the Canadians are great.I really don't think there is a worm that is great both cold and hot.I picked the Africans because it's always hot here in Arizona.Heck,when it's under 50 degrees here that is a cold day.If I lived somewhere with 4 seasons I would probably raise the European Nightcrawler.Go online to like organicwormfarm.com and read about them.They give details on each kind of worm.