radiant heat

But when the Fire Department determined the spaces were not capable of protecting the town’s entire population from the extreme radiant heat, it pivoted to sheltering in place — the last and most dangerous option listed in the old guide.

“A hydrated plant is absorbing radiant heat up until the point of ignition, and then it’s part of the progression of the fire,” said Moritz.

To deem a building worthy of “fire shelter” status, it must resist all of fire’s assaults: Its searing radiant heat that extends far beyond the flames, the falling embers capable of sneaking into any cracks to ignite whatever is inside, and the flames themselves.

The windows feature three panels of quarter-inch glass, which lessen the possibility of breakage in the face of scorching temperatures and protect the interior from radiant heat — one of the primary ways fires can enter a home.

Irvine Co. erected a 6-foot wall around an enclave on the north part of the neighborhood — where a Santa Ana wind-driven fire would most likely hit first — to protect the most vulnerable properties from radiant heat and keep low-flying embers out of the development.