I'm trying to describe a character in a story, but all I can think of is high pain tolerance. I think it's a bit weird in the scenario though.
Your character is stoic:
not affected by or showing passion or feeling.
especially : firmly restraining response to pain or distress —MW
Study could explain why some people are more stoic than others, researchers say
It's been a mystery why some people can withstand pain better than others. —Genes May Help Determine Your Pain Threshold
It's a simple word, but tough: capable of tolerating extreme strain, hardship, or severe labor.
Tough is especially applicable in a character description.
After years of military service, bar room brawls, and countless injuries without a word of complaint, no one doubted that Joe was tough.