Abstract: A fuel cartridge for heating food trays uses a liquid fuel and a wick. The cartridge has a container that holds the fuel and has a lid with an aperture formed in it. A flat rectangular fiberglass strip serves as the wick and is pressed against the lower side of the aperture. The lower ends of the wick extend into the fuel, and the central portion of the wick protrudes only slightly from the aperture. A metal ring can be used with the container to block wind currents.