No heat in my 2004 Chrysler Sebring convertible?

[Chase]

Over the summer my A/C was working on and off but after about 15 mins. of driving it doesnt work at all. Fall rolls around and i notice my heat is warm once i turn the heat on but then after a few minutes the heat turns cold or room temperature and i cant get it warm again unless the car is turned off for a while. Im more conserned about the heat then i am the A/C. If anyone knows what could possibly be going on please let me know! Thanks.
My car has never overheated or even got close to overheating. Since I have owned the car the temperature guage has not went past the middle line.

[br549]

Check the fluid level in the radiator. I'll bet it's low.