An AC emergency is any issue that impacts the safety or comfort levels of household members, seriously compromises the performance or longevity of the AC system or requires immediate service out of hours. Often, an obvious issue like not switching on, strange smells coming from the unit or leaking water affect AC systems but warm air blowing, refrigerant leaking or strange noises being emitted could also cause problems. Don’t take any chances. If a few simple AC troubleshooting steps don’t work, call an HVAC professional.