This paper describes a series of tests conducted to evaluate prototype fire shelters designed to provide enhanced thermal protective insulation in wildland fire burn-over events. Full-scale laboratory and field tests are used to compare the thermal performance of the prototypes with a fire shelter construction in current use in the United States. Laboratory tests showed that the prototype fire shelters outperformed the current shelter in providing fire-blocking thermal insulation in tests designed to simulate exposure to the intense flame conditions encountered in wildland fires. Field tests supported laboratory comparisons, but proved to be statistically inconclusive in differentiating shelter performance because of the variability inherent in thermal data obtained in field burns. This study confirmed the value of evaluating prototype shelter designs in laboratory tests capable of reproducibly simulating exposure to turbulent flames encountered in wildland fires.