Is there a heat reset switch on my Whirlpool dryer. It is about 5 years old

No, there is not usually a heat reset switch on non commercial dryers. If you're not getting heat, your thermostat, hi-limit thermostat, hi-limit fuse, or heater element is bad. You may be looking at a appliance repair service call. Hope this helps,
Rich
Western Appliance Repair of Boise 208-863-3702 (http://www.westernappliancerepairboise.com)