Fire shelter performance in simulated wildfires: an exploratory study

Abstract

Fire shelters are required equipment for most wildland firefighters in the United States. In this study we report flame emissive power and temperatures inside and outside fire shelters placed in one prescribed fire, five experimental field fires, and one laboratory fire. Energy levels radiated by flames varied from 70 to 150 kW m^–2 and lasted less than 10 min. Maximum fire shelter internal air temperatures reached 250˚C and occurred during the test with the maximum external air temperatures (1000˚C). Air temperatures inside the fire shelters did not show a strong dependence on flame radiant power, rather they correlated most strongly with external air temperature. We compare measurements from these tests with results reported by others. The data clearly indicate (1) the capability of the fire shelter to protect the occupant from radiant heating; (2) the susceptibility of the current design to convective heating; and (3) the significant decrease in burn injury when fire shelters are used.