We place ours on top of the water tank of our commercial coffee maker. As the water heats up for the coffee, it makes the metal lid heat up. It takes a few days, but they do dissolve without getting too warm. Years ago, we had a styrofoam cooler that came with a light bulb inside but it eventually cracked on the side and we tossed it. Up stairs in surgery, they keep a flat for the heart room in the blanket warmer.
We had a cabinet with a light bulb (to generate heat) but we were told that constant monitoring was required (like refrigerator temperature logs). So, we bought a warmer from Cole-Parmer that has a temp gauge.
We have an incubator with a thermometer that we use so that we can monitor temps. According to the PI and other sources we found, it should not be kept at constant temperatures above 86 degrees F because it may compromise the integrity of the product, so we keep the incubator at 85 and monitor.
