One other thing I could say is bitter cold weather is better than cold, wet weather right around that freezing/thawing temp. I've seen three dogs have seizures in those conditions from body temp dropping and subsequent hypoglycemia. This is because they get soaking wet and then cold as opposed to being just cold.
There is all kinds of info on the internet about the warning signs of this, how to prevent it, treat it, etc. but it is usually not until you deal with it that you realize it was something you needed to know about. What may seem to you like a gorgeous, sunny day to get the dog out towards the end of the hunting season or in the spring... a day that is finally twenty degrees warmer than the bitter cold days you’ve been having, may actually be a worst case scenario for your dog.
Regardless of conditions, a few things I've learned to always carry in my hunting vest are water (not only for drinking but flushing eyes after a skunk spray, a wire cutter for snares, etc., a multi-tool for cactus, porcupine quills, etc., and honey in case of the low temp/low blood sugar issue I mentioned. If you see that start to happen (dog gets wobbly or seems confused and “off” a bit) or your dog has already tipped over and started seizing, smear honey all over the dogs gums. I have seen all three of the aforementioned dogs pull out of a near death situation using that method. One was my own dog. In addition to the sugar boost, they need to be dried off and warmed up immediately (wrapped up on floor of pickup with floor heat cranked on high). Don’t wait for it to happen either, of you think it’s coming on or just moments away, be safe rather than sorry.
If anyone ever ever has questions on this, let me know. I’ve got more experience with it than I wish I did.