Question

What should you do if your temperature gauge moves up to just below the red zone?

Answer 1

Pull over when safe.
Turn off the car.
Let the car sit and cool off a fair amount.
Open the hood.
Use a rag or gloves to protect your hands from the heat.
Slowly very slowly with the gloves on after you have let the vehicle cool down a bit.
Open the radiator check if you have coolant in it.
If you don't you will need to refill it with the same coolant you use last time.
If you can't get coolant you can use water to get your car to a shop or home.
Using water can freeze when the temperature gets to low in winter
When water freezes it expands and will crack parts and can cause a lot of damage.
When you get your car to the shop or home flush out the radiator and fill it up with new coolant or antifreeze
Coolant or antifreeze sometimes come as a concentrate so you may mix it with water some you don't mix read the directions before you start.

Answer 2

If the temperature gauge moves up to just below the red zone,you should turn off your air conditioner and turn on your vehicle's heater. Then immediately find a mechanic or pull over safely and contact a road service.