www.heatedwetsuitreviews.com is about battery powered, heated wet suit vests that can be worn while using a jet-ski, sup, small sailboat, kayak ..... under a wetsuit, or under regular clothing while boating ..... and available for $225 .... if you look around.
It definitely warms you up because it warms up the core area ..... stomach-chest-back.
Plus, water sports in cold weather gives you a good excuse to go buy that $2.50 six-pak of day old, home made, yummy brown sugar donuts, at Heath's in Center Harbor ..... way in the back of the store.