Board Thread:General Discussion/@comment-32237043-20160626014030/@comment-35642216-20190127134557

The game files say he has 1 HP

But, um, he could have more since he sleeps

Sleeping gave Frisk extra HP above their max one: 30/20

Meaning sans could really have 1 HP, but has extra HP since he is sleeping a lot

Which would answer how he didn't die in Undertale for falling over his head, etc... because he has extra HP which wouldn't let him die