Wildfire survival bunker - photo

[EnginePaul]

"The killers are smoke inhalation (particulate matter, carbon dioxide, and carbon monoxide), heat, and being crushed by failing trees or structures."

I agree with this statement. At this moment, I'm breathing moderately bad air from California fires and can see ashes everywhere and having mild difficulty breathing even though I'm miles from the fires. Heat is bad but the lack of oxygen is the major factor. Poisoned air will override all.
But that shelter could help in some situations; better than nothing.