Lots of heated clothing is available that the Motorcyclists wear during winter available and here is a few websites that offer 12 volt plug in types, recharge battery types also. Just a FYI, but some of this could be used for fishing in cold situations. It can be priced alittle high, but anymore, the technology built into the product is very good.
Heated Clothing | California Heat
www.ventureheat.com
Heated 4 U, LLC - Heated Clothing Dealer - Maryland

Bikers swear by some of this gear as windproof and some is also water proof, but may be alittle bulky as for fishing.