A salt block can be heated on a gas or electric stoves or on a charcoal or gas grill. Some can also be heated inside an oven; check your manual or with the manufacturer to verify that yours can be heated using this method.If you are heating your block on gas, be sure that the block is not touched directly by the flames. Use a flame spreader so the heat will be more indirect.Whichever way you choose to heat your salt block, be sure you leave yourself enough time, as it can take 30 to 45 minutes for the block to reach optimum heat for cooking.