A worker who was working alone at a restaurant entered a walk-in freezer. When the door closed, the worker was unable to move the "mushroom cap" handle to open the door from the inside. Three hours later, the employer found the worker unconscious. The worker suffered hypothermia and frostbite.

The freezer door could not be opened because the push rod of the mushroom-cap handle was surrounded by ice and could not be moved without significant force. The freezer door was usually open while a worker was inside, so workers rarely used the mushroom cap. It had probably taken weeks or even months for dripping water to freeze inside the handle. Ice is more likely to build up in hot, humid weather when there is a greater difference in temperature inside and outside the freezer.

• Inspect and depress the mushroom cap release handle regularly so that ice does not build up. Make sure the cap can move in and out easily at all times. Do this as part of your regular safety inspections.
• Make sure workers know how the mushroom cap handle works and how to break the ice if the handle won't move. For example, try to turn or push the knob. A worker might need to kick the cap several times or hit it with a heavy object to break the ice inside.
• Follow written procedures for checking on the safety of a person working alone.
  
• Develop emergency procedures in case someone is trapped inside the freezer.