Battery Powered Mittens

My husband has been saying for many years that he was going to buy me battery powered mittens due to the fact that my hands are cold all of the time; especially in the winter. I have Raynaud's, which essentially is poor circulation in my hands and feet. Well, this year he finally gave me battery powered mittens which are designed to keep my hands nice and toasty warm. I tried them out briefly yesterday in the house, but the real test will come when I have to be outside for an extended period of time in the cold. However, it sounds like it will be a few days before I get to really try them out as we are suppose to have temperatures in the 40's.