Just tried out Rockwood and it's great. Very glad I bought 4 bags. I plan to store in my detached garage, which is un-airconditioned. I live in Alabama and it can get quite hot in the summers and in an unairconditioned garage I would think it could get up to 110 or 120 in the hottest of the hot summer days. At that heat level, do I have to worry about combustion of the lump? I'm probably being paranoid but just want to be safe. Many thanks in advance.