I have found a mini hot water bottle (those small ones that are meant for babies) to work pretty well for me. They don't weigh too much in the backpack but do help to keep you warm.
Type: Posts; User: hunterAT
I have found a mini hot water bottle (those small ones that are meant for babies) to work pretty well for me. They don't weigh too much in the backpack but do help to keep you warm.