I agree with both responders; I'm hunting with my second Lab in the sloughs of southern Alberta where we're lucky to get into November without solid freeze up. I've not vested either dog and never noticed either being cold or uncomfortable. One vest I do use on my current Lab is a skidplate for upland hunting. We have a lot of thorny bushes around here and the skidplate sure saves her belly. BTW since we're frozen up now the waterfowl hunting is restricted to field shoots with the birds coming off the river. There are still lots of geese around but not many ducks. Good hunting!