Whirlpool gas dryer little or no heat

Need a little more information like what is the model # of the dryer.

Then answer these questions:
1. Does the dryer heat at all? If yes, does it cool back down to room temperature within a few minutes?
2. Is the exhaust vent clear? To verify, disconnect the vent at the back of the machine. The amount of air that comes out there should be the same amount of air that comes out of the vent wherever it exits the building. If not you have a restriction.
3. If you have no heat at all, do you hear a loud click in the lower left of the machine when starting it? If you do, do you see the ignitor glow?