[andbberger]

power dissipation scales sublinearly in body mass, scales roughly as mass^.75

humans can dissipate 360W easily, though not necessarily comfortably.

that being said, the power usage is high. assuming uniform absorption, 4w/kg works out to roughly 200mw in the brain. here's a neuro paper that sets an optimistic limit at 40mw.

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3807567/#B34

OTOH, we pump a lot more than that (relative to mass) into fly brains during imaging, although they're not expected to survive much longer than the imaging session. the laser in our lab is about 1w, after losses from the optics path and pulse picking, the power on the brain is usually around 20mw