Here in Kansas we had negative and single digit temps which made for good hunting on the river. I did not take my dog out thinking it may be too cold for him to be wet outside of the water. What is a good temperature cutoff point for your dog? When is it too cold for him?

P.S.
while hunting without my dog and retreiving a duck, even though the deepest point was belly deep I thought it would be nice to take a swim in 8 degree weather.(I slipped and fell) it was about 1/4 mile to the nearest road and 1/2 mile to the truck. I went to the road and some passers by offered me the heat of their car while my buddies went back to get the truck. Thanks go out to all of them as I thought I was not going to make it. Either way, I can look back and laugh at the story now. Specially as my head went under and all I could think about was "is this how my dog feels in here?"