Tiny--I've never needed anyhting more stout than a SWK standard--even in a Michigan Winter. Although I have been known to wear kilt-johns under my standard while rabbit hunting or hiking in very cold weather. For the price, the SWK heavies are a good deal. I'd say get one if you want to try them out--but not because you HAVE to have one for the weather. (although, it makes a great 'excuse' to get another kilt or 2 )