Fire Shelter

All firefighters are required to carry a fire shelter when they are on duty.  An essential part of the certification requirements for firefighers is to attend annual refresher training where they must successfully deploy a fire shelter. 

Fire shelters are used in emergencies when a firefighter is trapped by a fire and has to find immediate protection.  Fire shelters are made of aluminum foil, silica cloth, and fiberglass.  These materials can protect a firefighter from radiant heat, direct contact with flames.  The fire shelter also provides a pocket of fresh air for the firefighter to breathe if he is forced to get underneath it during a burn over.

The highest priority for firefighters is to avoid being entrapped by a fire.  If a firefighter is accidentally entrapped, he must protect his lungs and airways.  The firefighter must dispose of all flammable items and get inside the shelter and on ground before the flames reach him.  The fire shelter should be deployed in a spot where there are no fuels on the ground.

The greatest threats to the firefighter who is trapped by a fire are burns to the body and inhalation of hot gases which can cause asphyxiation.  A person can survive for a short period if the air temperatures are at 149°C  (300°F).  The environment outside the fire shelter will easily exceed these limits, but the fire shelter may save the life of a person inside.  Experiments on fire shelters show that the air temperature inside the shelter rose 80°C (176°F) when radiant heat is applied for 300 seconds.  When direct flames were applied to the shelter for 40 seconds, the temperature inside the shelter rose an additional 50°C (122°F).  Heat flux of 5 kilowatts per square meter will lead to a second degree burn in about 40 seconds on bare skin.  Heat flux from 300 seconds of radiant heat and forty seconds of direct flame produced peak heat fluxes of 1.5 and 1.3 killowatts per square meter, respectively.