Basically what Buzz said, unless there is coolant loss or air restriction engines overheat from working to hard.
No steam from under hood or out the back while moving? Then you dont have coolant loss, so you pull over and remove the load from the engine.
The engine will start to cool off, you can also shift into neutral and increase the engine RPM to around 1500 to speed up the cooling.
This pushes the coolant through the engine to the radiator faster so it can be cooled faster, sounds counter intuitive but it works.
Again, no load on the engine.
You do not want to rev the engine with the transmission in park, you will overheat the transmission because in park the trans oil pump does not circulate the ATF on most cars.

 

I learned that the hard way. Now, if I have to make short trips, I keep going until the engine and exhaust heat up enough to dry up the condensation. It doesn't help the gas bill, but you can save yourself a lot of money and headaches on engine issues as well as preventing corrosion in the exhaust system.

 

If you drive it continuously for a hour or so once a week any condensation that builds up will evaporate out of the engine and exhaust.
We have to do this with my wifes car, every Sunday we go for a long drive and try to include a 15-20 min trip on the expressway to keep the RPM up for a little while.
Her battery will actually start to go dead because of the extra load from the wipers, lights, rear defrost etc. and the short trips.

 

I get the engine overheats from working too hard but why not reduce the load completely? It's not going to cool down any more at idle than it would running at speed. Water pump and the thermostat regulate that. The majority of overheating issues are poor cooling at the radiator either bad fan clutch or clogged rad. I still think your best bet at 220* is turn it off. Now 205-210 maybe pull over and let it idle with the heat on but 220 is too hot for comfort.

 

But if you turn it off you stop all coolant flow so the engine just gets hotter and hotter because the heat just builds up and without the coolant circulating to pull the heat away you cook the engine.
If it does not start to cool off after you remove the engine load and the heat continues to climb then yes, you must shut it off but you have to give it a few min.
220 wont kill the engine, 250 and its a boat anchor, 230 shut it off, 240 be very worried.
It is not actually considered overheating until it reaches 230.
Believe it or not 20* is alot of wiggle room.

 

How is the coolant going to get hotter if the engine isnt running I.E. combustion isnt happening??? I understand it's going to stop circulating coolant but if you continue but slow combustion and the coolant rate slows it's the same thing as coolant flowing fast and combustion fast.. It climbs from 220-240 very quickly if you keep it on.

 

The heat builds up because everything is already heat soaked, and as we know heat rises, so the heat from the crank case area and cylinder walls is going to rise into the heads and just sit there.
There will be some slow coolant flow from the hot coolant rising and then falling to the bottom of the radiator/engine as it cools but because it is a cross flow radiator and not a down flow (much more efficient) the heat just builds up.
Just because you shut the engine off does not mean the heat has stopped.
The heat from inside the crank case rises after shut down, the cylinder walls are still hot, everything that was hot will radiate the heat from them and the coolant will soak it up and just get hotter and hotter.

 

Im not saying the heat stops I'm saying the source of the heat stops. I know the temp will spike after the truck is turned off but when the truck is overheating it is very un likely it will cool off by letting the truck idle even with the heat on.

 

Regardless of pulling over and letting it run or shutting it off, why not pop the bonnet and prop it open as well to increase air flow and allow for more heat to dissipate?

 

Unless you have a sudden loss of coolant shutting off a overheating engine is the last thing you want to do, your truck do what you want but that is what you are supposed to do.
Most overheating is from to much load, i.e. climbing a long grade on a hot day with the a/c on and the entire family and the dog in the car.
Turn off the a/c, turn on the heat, pull over and let the engine idle and it WILL cool off.
When I was in mechanics school thats what we learned, when I drove truck thats what I did many times to cool off the engine, I've dont this trick in my own car, I've done it with a farm tractor, unless it is a air cooled engine or you have sudden coolant loss or a failed water pump this works each and every time.
I've had a truck overheat in the winter time, once I crested the grade and started on the downhill side the engine cooled back off so I did nto need to pull over.
Opening the hood does help to let the heat escape.