The law of thermodynamics still applies, so liquids will get hotter and pressure will increase which means it’s more likely to ignite. But the heat of new embers at the top of a flame is rather difficult to compare with that produced by even small amounts of liquid. Rather than thinking about boiling points, you might reasonably think of it this way – consider what you might see if you’re holding your hand over open fire for one minute; if someone did the same thing with an apple or orange (not free radicals but yes they can hydrate), what would happen?
Each individual airline sets their own safety standards according to their comfort level under the continuing guidance on international aviation safety standards found in ICAO Doc 9284.