He was talking about using 25 watt heating pads to heat yourself.
Last winter I was working on my car in 7 degree weather. It was intolerable.
For years I would take a pillow case and fill it with 4 pounds of brownrice. You microwave it for one minute for every pound of rice in the bag. It stays hot for hours and as the rice cools it reabsorbs moisture and you can microwave it over and over and OVER!
So I took a goose down vest that I had and sucked all the feathers out with a vacuum cleaner. I then added equal amounts of brown rice to the vest and sewed it shut. Then I put the vest in the microwave and heated it up. I put it on and it kept my core warm for hours while I worked on my car. Now I am not a math genius like Paul so I am not sure how much energy was used by a microwave in 4 minutes.
I just wanted to put this idea out there so I could get some feed back on it.
also of note there is a lot of 12v heated clothing at your local motorcycle dealer the stuff is expensive but with a good 12v power supply under your desk you could be comfy anywhere (in fact if using a desktop computer you could rewire one of the hard drive plugs and run it off the computers power supply)