HELLO MY AC BLOWS HOT AIR, WHAT'S THE PROBLEM?

I TURN THE AC ON AND IT BLOWS OUT HOT INSTEAD OF COLD

O,K, Is the compressor coming on? If you change the temp. setting , will it go from ambient air temp to HOT or does it not change at all? When the A/C is switch on , do the under-hood cooling fan(s) come on?Did this happen suddenly or has it been gradually getting worse? That info would be just a start.///////.....to much to ask? Or did you get it to a shop , hopefully , so you can get your A/C back! It's hot out!