Heard a pop heater started blowing cold air and car overheated

Hello, hearing a "pop" followed by no heat and engine overheating is an odd sequence. I don't know what you could hear the cause the concern. So, I'll go to the basics. If the engine is overheating, it'll be important to check coolant flow, engine temperature readings, thermostat operation, cooling fan operation. If there's no hot air in the vehicle, you could have a sticking thermostat, a temperature blend issue in the climate control, or some other kind of heater core related issue. Testing hands on is needed -- www.repairpal.com/repair-shops is a great resource to find shops near you.