Trying to find an electric heating pad that works in my truck's bunk

Title pretty much says it all. When I have a sore muscle or lower back or neck pain, I love to use a heating pad to soothe the pain..
So I decided to take my Sunbeam brand heating pad on the road with me. Back got sore.. Tried to plug it into my inverter/power strip/12v adapter- Nothing worked. The lights would just blink..
Checked the tag on the heating pad and it specifically says it won't work with any sort or inverter or anything like that.
Do yall have any 12v or Inverter friendly heating pad suggestions? This is my first truck with an Apu & inverter.

Thanks everyone

 

You can buy a 12volt mattress heating pad made by electro/warmth they last for years and warm the top side of mattress and will help your back feel more comfortable in morning, they were for sale at the T stops but now you must order them from the website

 

That is perfect. Thank you, just ordered one

 

I use the cheapest heating pad Dollar General sells and it works fine. I have a 1500 watt factory inverter in my Cascadia

 

Just for your entertainment

 

Both of my heating pads work with my inverter in my KW no problems. 1 regular heating pad and 1 far infrared heating pad. Try a different heating pad I guess.

 

What brand is your far infrared pad? Been looking at those as well

 

Thermotex platinum. Think I paid $149.00 for it. The inverter I have is an Eaton true sine wave. It came with the truck. Works real well.