Every year numerous uncontrolled fires happen worldwide. These fires are more likely in three spaces—natural areas, structural buildings, and vehicles .
Wildfires are very common in natural areas; they are also known as forest fires, bush fires, vegetation fires, etc. In this type of fire, the dry vegetation may ignite and start burning due to some natural disaster (eg, lightning, volcanic eruption, sparks from rock fall) or they may be caused by human error. Although wildfires usually happen in an uncontrolled way, since 1970, these fires have also been set intentionally in a controlled way to balance the ecosystem of many places. The main feature of wildfires is the extensive flame size (more than 1 m high) depending upon the availability and moisture content (or dryness) of vegetation . Furthermore, such fires propagate rapidly in windy conditions and their pathway changes indeterminately depending upon wind direction. Many researchers have attempted to graphically represent the direction of wildfires, particularly for the safety of firefighters who work in hazardous wildfire conditions [43,44]. Researchers corroborated that wildfires always propagate in the direction of wind and can spread as fast as 10.8 km/h in forests and 22 km/h in grasslands. Depending upon various factors (eg, moisture content of combustible vegetation, and wind speed and direction), the temperature and heat flux in wildfires can
Thermal Protective Clothing for Firefighters. http://dx.doi.org/10.1016/B978-0-08-101285-7.00002-2
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reach up to 1700°C and 150kW/m2, respectively . The high temperatures and long duration of wildfires may lead to a flashover condition of ignition of tree canopies from beneath.