My truck gets hot while driving, not ideling. Only when the rpms get up. I changed the thermostat still hot?

I changed the thermostat, still getting hot. While ideling runs great. Start driving, as the rpms get up engine gets hot.
My truck gets hot while driving, not ideling. Only when the rpms get up. I changed the thermostat still hot?
The other answers are good and you should look into that. Also you may want to check this also, I have seen it happen a few times.

It is the beginning of a blown head gasket or crack developing in the head.

As the RPMS go up the effective compression goes up and the metal in the head and block expand too, this mostly causes a head gasket

leak. Let some of the coolant out of the radiator, get a block checker kit, get to operating temp and then bring rpm up to where the engine starts to over heat and use the block checker, if it changes color you know its a blown head gasket, and make sure you magnuflux the heads for cracks. It is rare but I have seen it happen a few times. And one time I never figured out what it was till I took off the heads and found the Head gasket split

Hope this helps and good luck
My truck gets hot while driving, not ideling. Only when the rpms get up. I changed the thermostat still hot?
Sounds like a volume problem to me, check the belts to make sure the water pump isn't slipping under load.
make sure ur rad isn't plugged, check belts, make sure they arn't loos and slipping, check coolant circulation.