Many folks have a difficult time believing that this method works.
But it does ...quite well actually. Scroll to near the bottom to see how I am able to control the temperature. A desklamp with a 100 watt bulb placed over the drum (about 2-3 inches away from the rotating drum) as it rotates keeps everything "toasty warm" as they say. If you look at the picture with the colored measuring cups, you can see the base of the lamp attached to the green shelf unit.
The lamp is an inexpensive version of this model. (search the net)
The link did not work properly. Just look up "gooseneck lamp" and you will see what I mean.