Next, get some rocks from a dry location or a few more of those bricks. Then, fire up the grill or build a fire outside and throw the rocks or bricks in the fire to heat them up. Let them sit for about 45 minutes and then scoop them out with a shovel. Get all the coals and sparks off of the bricks or rocks. Drop them into a stainless steel cooking pot. (Other types of pots may get damaged by the heat, and galvanized buckets can release toxic vapors under such heat, so stick with the steel pot.) Carefully bring the hot rocks or bricks inside and set the pot of hot stuff on your heat-proof platform. Repeat as needed every few hours.