We went to the Macy's Thanksgiving Parade last year and I had these. They are amazing! They really do keep you warm the entire time!
Will warm you up! I'm a big fan of these hand warmers. My hands get so cold, so now I don't have to worry - I can just bring this with me if I am going to be outside and it warms me right up. It lasts for hours. Unlike the disposable hand warmers, there are three choices of temperature, you can recharge it so it's always ready, and you can turn it off when you go inside. I've used this on my hands and my feet when it's cold, but also on my back and shoulders when they were feeling sore.