Wildland firefighters operate in a difficult environment where a variety of factors including topography, vegetation and quickly changing weather and fire conditions can lead to great risk of injury or death from burnovers or entrapment.
There are various models that provide firefighters with estimates of safe separation distance: the distance between themselves and the flames necessary to reduce the risk of burn injury. One widely known model from a 1998 study suggests that firefighters should have a separation distance of at least four times the height of the flames. However, this and other physically-based models for estimating safe separation distance have known limitations such as using only radiant heat transfer, no slope influence, no inclusion of injury mechanisms apart from burns to bare skin, and no field validation.