503
xkcd #3124: Grounded
(imgs.xkcd.com)
Title text:
We should have you at the gate in just under two hours--two and a half if we get pulled over.
Transcript:
Transcript will show once it’s been added to explainxkcd.com
Source: https://xkcd.com/3124/
This made me curious if planes use "free" excess heat from the jet engines, same as a car would, or if they need to burn fuel to heat the cabin. And it turns out the latter is the case, so not only could the heaters probably not keep up, attempting to even do so would have wasted a ton of fuel.
Fuel that was already being burned at a high rate because of flying down in thicker air.