How well does the NiMH batteries hold up to hot environments such as the glove compartments of my cars. I try to keep flashlights in each of my cars and nothing is more frustrating than needing a flashlight in an emergency situation and the batteries are dead. I have been using LiOn (18650 rechargables) for this situation and pulling them out for a recharge every couple of months. Would NIMH batteries be better suited to this application?