Temp Gauge going into the red

We have a 2002 Ford Focus Wagon. Just recently I have had to use the heat, it didn’t seem like the air coming out of the vents was getting any warmer and then I noticed that the temp gauge was into the red. The next time I drove the car the gauge again went into the red and it was only about a 5 mile drive at the most.

What is the possible cause?

Low coolant

Agreed. Check the coolant in the radiator, when the engine is cool. Checking the coolant overflow bottle isn’t sufficient.

Man you guys are quick! Thank you for your answers and that is what I will do tomorrow morning.

Hint, don’t try and drive it with the coolant that low.

Your thermostate could be stuck shut so car over heats. they are easy to change an cheap too.

I wanted to let you guys know that it was the coolant. I refilled and it was fine. Thanx!!!