Refrigerant is circulated through a vapor compression system including a compressor, a gas cooler, an expansion device, and an evaporator. When a sensor detects that frozen water droplets form on the evaporator, a valve positioned between the discharge of the compression and inlet of expansion device is opened. Refrigerant from the discharge of the compressor bypasses the gas cooler and enters the inlet of the expansion device. The high temperature refrigerant melts the frost on the evaporator. As the frost melts, the passage of the evaporator is opened to allow air to flow through the evaporator.