I've hunted cold alot with a dog and is not so hard on them if you are on dry land so the dog can roll to dry and be a bit comfortable. I'll even start a fire to warm up around. In a boat/canoe, or on snow, and it gets alot tougher on the dog. As mentioned, the wind is a biggie as well. My Labs have had swollen anal glands from the cold water a couple of times,i.e.-they can hardly wag their tail. You were smart to leave her in the truck as their heart just tells them to keep working. I will try to get a lot of calories in them as well...hamburger, sausage, etc. Often, they will shut down eating when worked hard so something they love usually works. I have never used a dog field hunting so I can't speak to that. have fun...Mauser
The greatest duck call known to mankind?....A fresh cup of coffee from the Thermos.