It sounds backwards: it's 104° outside and your air conditioner is covered in ice. But a frozen evaporator coil is one of the most common summer service calls in the Valley, and running the system while it's iced up can destroy the compressor, turning a small fix into a big one.
The two usual suspects
Restricted airflow is the most common cause. The coil gets cold enough to freeze moisture from the air when not enough warm air flows over it, usually thanks to a clogged filter, blocked vents, or a failing blower motor.
Low refrigerant is the other. When refrigerant leaks out, the pressure in the coil drops, and lower pressure means lower temperature, low enough to build ice. Refrigerant doesn't get 'used up.' If it's low, there's a leak that needs finding and fixing.
What to do right now
Turn the cooling off and set the fan to ON. This thaws the coil without the compressor fighting the ice. Check the filter and replace it if it's dirty, and make sure vents are open. Once thawed, which takes a few hours, try again.
If it refreezes, stop. Repeatedly running a freezing system is how compressors die. At that point it's likely a refrigerant leak or a mechanical issue, and it needs a professional diagnosis. Call us at (559) 274-1300 and we'll find the real cause.