Poopscoop – I think you have the surface area to volume ratio the wrong way round.
Roughly, if you are twice as tall as a child, you have four times the surface area, but eight times the mass. (Yes, I know people aren’t spherical).
When length is twice as big, it is in one dimension…
but area is twice as big in two dimensions. 2 x 2 = 4.
and volume is twice as big in three dimensions. 2 x 2 x 2 = 8.
Thinking about the units might help visualise it:
Length in metres.
Area in square meters.
Volume in cubic metres.
I think small mammals survived the dinosaur extinction because they were mammals. Small dinosaurs didn’t survive it.
My experience with children is they have a faster metabolism when they are running around playing, but can then get chilled through really quick.