I have a question regarding central air issue. I noticed that on the thermostat , its 84 degrees and the central air is set for 78. Before it was set at 74-76 degrees and it was working fine. I went outside and the pipes are iced up. What do I do. I shut off the central air for 2-4 hrs. I turned it back on and its iced up again. Can you help me please

1st check/make sure filter is clean
2nd condenser coil must be clean
3rd evaporater coil must be clean
2 to 4 hours might not be enough time for all ice to melt away, make for sure inside condenser and the evaporater coil inside the furnace

Make sure when all is on that both fans are working inside and outside fans
If the problem is still there, you`ll need to call the hvac tech to check refrigerant