Manual defrost is a process used in some refrigerators and freezers to remove ice buildup. Unlike automatic defrost systems, which periodically melt ice, manual defrost requires the user to turn off the appliance and let the ice melt naturally. This is often necessary to maintain efficiency and storage space. To perform a manual defrost, the user typically empties the appliance, turns it off, and allows the ice to thaw. It may take several hours, and placing towels or containers to catch the melting water is recommended. Once the ice has melted, the interior can be cleaned before restarting the appliance.