For the life of me I can't seem to figure out how to turn them off once they are on. High or low, that seems to be it. (2000 Silverado)

Just cycle through the settings. High, Low, Off

Just cycle through the settings. High, Low, Off
There is no off, just high or low. I can press the button a million times, once they are on, they are on until I shut the truck off.

There has to be an off setting. If not, check the manual and pull the fuse.

I would check the manual OR pull the fuse :D

If you have the botton style you should see the light when it is on hi or lo no lite its off. It takes a long time for that seat to cool of i have noticed the leather really holds in the heat. If that is not it replace the botton switch.

Must be the button. Once you turn it on there is no turning it off.