What to do when my Audi A6's AC is blowing hot air?

I recently bought a used Audi A6 and everything was working fine until the AC started blowing hot air. What could be causing this issue and how can I fix it?

First of all, check your car's refrigerant level. If it's low, then you may need to recharge it. If that doesn't solve the issue, then there may be a problem with the compressor or condenser. I would recommend taking your car to a reputable mechanic to get it checked out.