To quantify the problem I wrapped one handle in insulation with a thermometer inserted next to the bottom part of the handle. After 10 minutes of running at full speed, the thermometer rose from 38 degrees F to about 39.5 degrees. A 1.5 degree increase in temperature is of little value as a warming device. I'm sure you have some way of measuring the output from the warmers. What should I expect? Thank you.