AC blowing out warm air

Is this a window unit or a central a/c unit?

Either way... check to make sure the coil isn't frozen up (let a/c sit shut off for about 20-30 min)
Check your thermostat if it is central air. Sometimes programmable thermostats are confusing
If it is central a/c... go outside. Is fan running? Is the small cooper line warm and large line cool? They should be. Even if fan is running, the compressor could be out. I just spent $1500 on my central a/c unit Friday because compressor was burnt up. If it is really hot, your copassitor (can't spell) could be hot and burnt up.