I don't think it matters. I bring my Howatt Hunter, that I never un-string, inside where it is around seventy and then outside in very cold weather for a day of shooting (sometimes below 0F) with no problems. I have done this for years. When whitetail hunting from a friend's house in the country I used to leave it in the truck to keep it the same temperature as I was hunting in, but did not notice any difference from bringing it inside. I also hunted in the rain with freezing / unfreezing temperatures in an un-heated tent last year and no problems - except for trying to get clothes dry! Fiberglass backed bows are tough and very stable. Now, if I was not using a fiberglass backed bow with a good finish and carbon arrows things would be different!