The thermal load of the hot wood would burn it even if it extinguished the visible flames unless you could cut off all oxygen flow.

Is "thermal load" in this sentence an elaborate term for "heat", or is there more nuance that I'm missing?

You can have a tiny amount of material be very hot, but you could cool it with a small amount of water. Its thermal load is low.

If you have a large amount of material be moderately hot, you'd need a lot of water to cool it. The thermal load is high.

In these sentences, you're using "hot" and "cool" to refer to temperature, and using "thermal load" to describe what physicists and engineers unambiguously call "heat," as in the amount of thermal energy held within a specific object of a certain mass, heat capacity, and temperature. In my admittedly limited experience with thermodynamics (currently in grad school for physics), "thermal load" seems to describe the exact same thing as heat, except it's less common. In fact, it initially confused me because of the concept of "thermal mass," which refers to the total heat capacity of a given object = mass * (heat capacity per unit mass).

Sounds like a great way to make the world's biggest backdraft...