Nope, sorry, putting your hand flat over the pile won't tell you anything, it will not be warm on the outside. You would have to put your hand down in toward the middle of the pile. If you are squeamish about that (there is garbage and earthworms and stuff in there), get a thermometer.
They make special thermometers for compost piles:
[url=https://www.google.com/products/catalog?q=compost+pile+thermometer&um=1&ie=UTF-8&tbm=shop&cid=17868496188406507679&sa=X&ei=CNYnT-KPIeeq2gWNxZDkAg&ved=0CJUBEPMCMAI]compost pile thermometer[/url]
If you are all in to the science of it and want to track how your pile heats up and how hot it gets, and when it starts to cool off, you would need one of those. Me, I stick my hand in to get an idea of what is going on....