My better nine-tenths must have noticed how I suffer outside on cold, dark viewing nights.
So, she found and bought (c.$150) me a battery powered, electrically-heated vest!
Apparently, motorbike buffs like them, as do skiers.
I don't have any connections to the company that produces these vests, but I can certainly attest to how warming they are! And up to 4 hours of it - centred on the lower back. Bliss!
http://www.jett.us.com/news.htm
My only criticism is the use of the 'off' switch to change the heat output - seems rather illogical!
Dean