I spent quite a lot of money over the years on gadjets to keep me warm. Gell pads, heated waste coats and electric insoles with AA battery packs etc. Each time I bought something I felt I was closer to the ideal, but looking back I should have gone straight out and bought the Gerbing jacket with temp modulator. It warms me front and back, collar and sleeves. The modulator cuts down power consumption and I have yet to trip out the F800GS accessory socket.
It would have been expensive had I not bought it s/hand of e-bay but I would now be prepared to pay full price for one its that good.
As Tim says, the jacket works best over a long sleeve thinsulate type shirt over a vest, no jumper. I then have my thermal gortex liner and jacket over everything. With the heater set low the whole kit soon warms up nicely. It would be a cold blooded person who could take the heat if no temperature controller is used though.
Back to the original post, I tried a similar pad designed to keep new puppies warm (Again off e-buy). I found heat at the top of the back was not the best location, lower down over the kidneys is better. My experiments did convince me of the value of heated clothing and at 35 euros its not too expensive. The problem is once you find the luxury of heated clothing you will probably soon buy a jacket and the 35 euro will go a long way towards its purchase.
