It's way past midnight and it's been a really long night at the restaurant where you work. You only need to repair that broken shelf in the walk-in freezer and then you can go home. After you enter the frigid air, you decide it might be a good idea to get your sweatshirt -- the shelf may take a few minutes to fix. You push the door but nothing happens. Then you try pressing the safety release handle and realize the shelf isn't the only item in disrepair. You think, "Now what am I going to do -- why did I agree to lock up by myself tonight?" Since you're all alone, there's no point in ringing the safety bell. You glance at your watch and realize it's going to be about six hours before the breakfast crew arrives…
What do you do in a situation like this? First, let's take a look at your surroundings to see what you're facing:
- The temperature is probably somewhere between 0°F and -10°F (this would meet the FDA requirement for walk-in freezers).
- The ceiling, walls and door are four to six inches thick -- made of some kind of insulating foam like urethane covered in sheets of galvanized steel, stainless steel or aluminum
- The floor is also covered in galvanized steel, stainless steel or aluminum.
- There are stainless steel shelves loaded with plastic bags filled with meat, poultry, fish and other frozen foodstuffs.
- A single vapor-proof fixture provides dim lighting.
- A row of thick plastic curtains hangs in the doorway.
Basically, you're inside a tightly sealed, extremely cold, giant metal box. You need to worry about:
- Air supply
The normal core body temperature of a healthy person is 98.6°F. Hypothermia occurs when a person's body temperature drops significantly below normal:
- Mild hypothermia - core body temperature between 93.2°F and 96.8°F
- Moderate hypothermia - core body temperature between 73.4°F and 89.6°F
- Severe or profound hypothermia - core body temperature between 53.6°F and 68°F
A person suffering from hypothermia will become tired and confused. He or she may have slowed breathing and speech followed by a loss of feeling or movement of their hands. Persons with severe hypothermia are at high risk for cardiac arrest and possibly death.
In order to keep hypothermia at bay, you need to maintain your core body temperature. Your best bet at doing this is by fashioning some kind of protection from the cold.