[PaulDavisThe1st]

It is rarely the case, indeed.

However, in incidents like e.g. the Fort McMurray fire (Alberta, 2016), this is precisely what happens. One property with a heavy fuel load fanned by strong winds (i.e. plentiful O2 supply) gets hot enough that it causes ignition in a neighboring exposure.

In Ft. McMurray, there were documented cases of an entire 4+ bedroom house being reduced to ash in roughly 5 minutes. The heat generated by that process is easily sufficient to cause ignition in buildings <typical suburban layout> apart.

[hn_throwaway_99]

Even in that case I'm sure a huge part of the heat transfer is convection, especially with the high winds.

Comment I was replying to was talking about IR igniting things by shining through windows, which I believe is mostly bullshit.