Car trouble

Was it blowing any air at all? or was the air just not hot.  You might need a heater core. and as far as overheating check your radiator, check the fluid levels. i know on my car there is a line where the antifreeze should be at when the car is hot and a line for cold so give that a look.

yeah it was blowing cold air. and i checked fluid and its good

If its just blowing cold air its probably the heater core. And as far as the other issue its possible the fan is fucked up like something electrical, use to happen to my friend his electric fans would shut off and his car would get hot as shit.

There was a thread made a few weeks ago that was similar to what you are describing.

https://www.newschoolers.com/web/forums/readthread/thread_id/328528/

ah that would suck if you had a blown head gasket...its a possibility sounds like u have alot of similar problems as that other guy.

Over heating could be the thermostat which is pretty cheap. checl our anti freeze and see if there is oil in it, if there is oil in it its most likely your headgasket.

another sign it is you headgaskets is if you exast is filled or has white smoke in it.  that means your burning coolant.  I would check the thermostat as someone esle said that may be the problem.  Also i would check to see if your fans are turning on or not.  if they are not turning on then you may have to bypass the electrical and jimmi rig your fans onto toggle switched.  it looks like shit but it gets them to work.  i know about these problems because my 95 lumina had the headgaskets blow out and i had to replace them.  plus the engine was always overheating and the thermostat went plus the fans quit working.  i narrowed it down to a short is the wiring harnes but didn't feel like searching all the wires so i just bypassed it and hooked up the toggle switches.  as far as the no heat thing when the heater is on i would say that you either have an air bubble in you heater core or it is shot.  they are a bitch to change just like the headgaskets.  Goodluck...

could be a thermostat, but prob a head gasket: common on subarus 2.5l w/ 80k-150k miles.  (My 98 blew one, similar symptoms) even if the coolant looks full you could have an air pocket int he system that prevents the pump from working...  if the coolant looks dirty sludgy may be a blown head gasket

if you notice your car overheating its always smart to pull over and wait for it to drop back to normal, just turning the fan on will help a little bit, but if you keep driving its still possible to overheat your car.
it's possible to get air bubbles in your cooling system which will cause the temperature to spike for a little bit, then go back to normal.
take it to a tech

Thermostat is what I'd try first.

1. Check thermostat
2. Radiator

3. get a cold air intake. (it will give you performance gains anyway (5-10HP), and make your car sound better.. haha)

BOOOOOOOOOOOOOOOOOOOOOOOO!       -200
getting a cold air intake will NOT give you 5-10 hp. honestly it won't give your car ANY performance gains at all.
it will NOT fix any of the problems you have in your car, but most likely give your car more problems, because your car isn't used to the different intake system (getting a short ram on my wrx made it tick more than normal when it was cold) besides, subaru actually has a very efficient intake system, good for a lot more hp than your car can produce. i won't lie though, it will make your car sound cooler. that is a positive... but honestly its  redundant, because you won't gain anything in performance.

also if you have a CAI in your fender and drive through a deep puddle, there is a good chance you will flood your engine... guess what that means. new block. not fun.

so basically disregard that statement. and if you're really worried about your car TAKE IT TO A TECHNICIAN!