Turn cooling off
Continuing to run a visibly frozen system can make diagnosis harder and may worsen the problem. Let the system thaw before normal operation is attempted.
Airflow matters
Restricted airflow is one possible contributor, so check an accessible filter and blocked vents. Other causes may require refrigerant, coil, blower, or control testing.
Do not add refrigerant by guess
Refrigerant work requires proper diagnosis and handling. If icing returns after basic airflow checks, arrange professional AC service.
Safety note: If you smell gas, see smoke or fire, suspect carbon monoxide, or believe there is an immediate safety danger, leave the area as appropriate and contact the relevant emergency or utility service. Do not treat an active safety emergency as a routine HVAC appointment.