Just FYI, when you are talking about a solid piece of meat, the inside cannot grow/harbor bacteria. Bacteria get on the meat during the harvesting/packing process. They rest on whatever part of the meat is exposed to the air, packing equipment, workers' hands, etc. When you are considering ground meat, quick and proper internal heating is very important, because the "inside" of your burger patty or whatever is made up of a jumble of ground meat, all of which has been exposed to contaminants and all of which could harbor microorganisms. When you are talking about a solid piece of meat - a roast or a steak - you need to be concerned with the outside, or exposed, part of the meat being fully cooked. That is why you can safely consume a rare steak or slice of roast, while it is not recommended to ever eat a hamburger with pink in the middle.
FWIW, I cook meat pretty regularly when it is frozen solid. It may add an hour to the final cook time, but have never had any problems. I also start on high for the first hour or two, then turn it down to finish cooking. Remember that one hour on high is equal to two hours on low, and adjust your cooking time accordingly.
