It’s the middle of summer, the temperature’s pushing into triple digits, and you’re stuck in traffic. Suddenly a light on the dashboard comes on; it looks like a thermometer. Your car’s beginning to overheat.

What should you do?

First, if the air conditioner’s on, turn it off; if it’s off, turn it on.

Sound goofy? Well, the air conditioner is supposed to start the cooling fans running at full speed. If the car overheats with the A/C off, the fans may not be working from the temperature switch; turning the A/C on may get the fans running and cool the engine back down.

If the A/C was on, obviously the fans aren’t helping, and the A/C just adds more load and heat to the engine. So turn it off.

In either case, set the temperature on the A/C or heater controls to hot and put the fan on high. That opens the heater core and causes the fan to blow air over the fins. It’s like adding a small radiator to the cooling system. Of course you’ll need to open the windows all the way to let as much of that heat out as possible.

You can also try putting the transmission in neutral and pressing down a little on the gas to raise the idle. That gets the water pump moving faster, to get the coolant moving through the cooling system. Not too much; you don’t want to overrev the engine.

And turn off any accessories you don’t need. Those devices draw electricity. The alternator has to work harder, creating more heat.

Now keep an eye on the temperature light or gauge. It should start dropping almost immediately. If it doesn’t get down to a safe level within about a minute, you’re done: Get over to the side of the road, shut the engine off, and call for a tow truck. Don’t keep running the engine or it’ll burn up.

If the temperature does drop when you do these things, get your car to a repair shop as quickly as possible. You may have a sticking thermostat, a radiator leak, or a problem with the cooling fans. Get it checked out and repaired before going any farther.

Your local Cottman center can check your car’s cooling system and make any repairs you need to keep it running cool through the summer, no matter how high the mercury climbs. Give them a call and set up an appointment right away.