We live in a cold climate.  So, it goes without saying that you should keep your equipment as warm as possible since bringing it into a warm environment from a cold one can cause severe condensation to form. This will cause rust and can permanently damage electronics.

When this is not possible, put your equipment in a ziplock-type bag, close it, leaving it puffed up (but, don't blow into it). Bring it inside and it will condense on the OUTSIDE of the bag only.

As time passes, the item will gradually warm up and condensation should not become a problem.

If it gets really damp, put it in front of a fan or hair dryer set on "cold." This will not only cause evaporation, but will blow the moisture off into the surrounding air.