My car is overheating and when I turn on the heater it blows cold air

Hi - I am Dave, contributing to RepairPal and providing expert advice since 2010. A cold heater while the engine overheats is usually a sign of no coolant flow - such as with a thermostat that is stuck closed, not allowing coolant to circulate through the engine to cool it - let alone through the heater core to create heat inside the cabin of the vehicle. If you had a stuck thermostat, I would expect your vehicle to overheat rather quickly and fully - as coolant will not flow. You did not provide many details, so that is my best guess at this time. In any case, do not operate the engine at all until you get this resolved. An overheating engine can cause major damage quickly - and may already have done so - so it is best to get expert assistance as soon as possible - near you https://repairpal.com/auto-repair-near-me Click the link or call us at 877-913-1554. We'll gladly find you a certified RepairPal shop in your area.