How'd he get the water hot? Pls don't tell me he used that camping cooker he just ubilt for that...
It is actually fairly safe. Even though the wood at the bottom of the "barrel" (it is square, weird choice of words they had) is hit directly by the flame (which I doubt. surely he engineered some margin?), as it heats up the water above will boil and keep it at around 100 degrees on the water side. Which will in turn keep the wood from burning all the way through for quite some time.
Eventually it should still do so though, or even when it has just gotten far enough, causing someone in it to break it. But then it is STILL safe, because the water will flood in and drench the flame tool, removing the oxygen and fuel it takes from the air, to work (or is it merely outputting localized heat that turns whatever air is above it into a plasma? In that case the compartment can be flooded from the start, making it turn water into steam, that then spreads out to the sides of the wood covering it where it can escape (and in the process it turns back into hot water, never really escaping). Though the steam if it gets far enough before recondensing, is likely to damage the wood around it similarly to why it can activate charcoal or rust iron very effectively).
edit: since ppl keep on reacting "helpful" to this comment, I do want to point out explicitly that I quite literally said the water-side will be capped at 100 degrees. This implies that it is
not capped at human temps, and while convection and evaporation should irl help a lot (which is why you can bath in a metal barrel if you just add some wooden flooring, if the fire is regulated properly),
I were trying to make a joke out of "100 degrees water = safe, lul" while still referencing why it is safe to bath in fire-heated baths (if the fire is weak/distant enough), and that while wood might eventually burn through it should still be slow enough you can probably get
at least one use out of the wooden bath (guesstimating wildly with no actual experience on the subject :d). Like sure, you can boil water even in a plastic bag - but that doesn't make the boiling water any safer to stick your hand down into
