My car's temp goes up and my heat blows cold air, then it goes back down and then it blows out hot air? :eek:

Air pocket in cooling system. Low coolant level. Possible faulty thermostat. There's a good start for you.
Good luck.

Kitch is correct.
Inspect for low coolant. If the coolant reservoir is low or empty, you will need to have the coolant loss diagnosed.
What is the mileage, year, make and model of your vehicle?

my car's temp goes up and my heat blows cold air, then it goes back down and then it blows out hot air??:eek:
Thank You Guys So Much For Responding!! It's Very Appreciated... I went and had my oil changed and the guy at the oil place told me I had an antifreeze leak on my in take manifold... I don't think that's what it is... I had just got my thermostat changed and it was never leaking antifreeze before I got the thermostat changed so I think that is what it is it's not a big leak just a little one my car doesn't overheat and the oil change guy told me he'd do it for 500!! I think he was just trying to scam me... I have a 97 chevy monte carlo

Thank You Guys So Much For Responding!!! It's Very Appreciated...I went and had my oil changed and the guy at the oil place told me i had an antifreeze leak on my in take manifold...i dont think thats what it is...i had just got my thermostat changed and it was never leaking antifreeze before i got the thermostat changed so i think that is what it is it's not a big leak just a little one my car doesn't overheat and the oil change guy told me he'd do it for 500!!!! i think he was just trying to scam me...i have a 97 chevy monte carlo
That price is inline for your car, if it includes both upper and lower gaskets, parts and labor.
Get this in writing.
You may still want to shop around and get more estimates. Ask about the technicians credentials and about repair warrantties.