Cold weather can cause skin allergy in dogs.
It is a rare skin condition that most of the time happens in short hair dogs after going outside on a cold day or after being exposed to air conditioning, and may cause hives on body or swollen face.
Cold contact urticaria is the he medical term for it, and antihistamines seem to be effective in the treatment of this condition. Avoidance of cold weather and wearing jacket will prevent cold contact allergy.