The effects of wildland fires on cavity-nesting birds and bats, as well as fossorial mammals and burrow-using reptiles, are of considerable interest in understanding faunal risk in wildfires and the evolution of sheltering behavior.  However, little is known about the degree of protection afforded by various animal shelters in wildland fire events.  Utilizing NIST’s Wildland-Urban Interface Fire Dynamics Simulator (WFDS) and experimental data, we explore the effectiveness of common shelter configurations in protecting animals from combustion products and high temperature gases.  WFDS simulations were created to estimate combustion gas temperatures, velocities and concentrations at heights of 2 to 20 m over a range of wind speeds, fire power fluxes, rates of spread and canopy densities.  Fire spread past single- and multi-entrance ground shelters (burrows) was also simulated. Field measurements of CO levels and gas temperatures around and inside of single entrance shelters were collected during prescribed burns for model validation.