Temperature gauge in the red? Do this right now.

1. 01AC off, heat on highIt sounds backwards, but blasting the heater pulls heat out of the engine. It buys you a minute to get off the road.
2. 02Pull over and shut it offAs soon as it’s safe. Driving a hot engine can warp the cylinder head or blow the head gasket.
3. 03Hands off the radiator capThe system is under pressure and can spray boiling coolant. Pop the hood to let heat out, but leave the cap alone.
4. 04Wait, then lookAfter at least 30 minutes, check the coolant reservoir. Look for puddles, a split hose or a broken belt.
5. 05Top off only if it’s coolIf the reservoir is low and the engine is cool, adding coolant or plain water can get you a few miles. Not if there’s a big leak.

Tap each step as you go.