I have a common 110v home heating pad. I only used it occasionally, by folding it over the tube. It was uncomfortably warm, but my BBQ thermometer said it was only 104F.
For the last few weeks I’ve been using it conscientiously. It gets hot enough I sometimes turn it off for a few minutes at a time to get some relief. Instead of just folding it over the tube, I’d wrapped it tightly around and held it in place with a couple of loops of paracord and a couple of those spring-loaded “stopper” cord clamps.
Last night I dug the BBQ thermometer out again and checked the temperature. Then waited and checked it again. Hmm.
128.8F.
Sombeech! No wonder it felt hot.
On the downside, it didn’t seem to be causing any damage on my shaft. But I’ve also been using it on my scrotum, and it is continually irritated, sometimes peeling. There’s no blood flow in the scrotum like there is in the shaft, so it was probably getting a lot hotter than 128.8F.
There appears to be a difference in temperature between “just folded over the tube” and “tightly wrapped.” Or the temperature control in it is going out.
I found the add-on temperature controller hanging with a bunch of computer cables. Later today I’ll hook it up. Vacuum hose, power cord to the heating pad, and now the thermocouple and probe… [sigh].