Make no mistake, most gas grills are hot enough already, but if yours is a little on the old side or you're having trouble getting it hot enough to cook your food, here's a simple way to hack your grill: pack lava rocks around the burners. You won't make the actual grill run hotter, but you will retain much more heat under your cooking surface, which means deliciously browned grilled meats and veggies. More »