system
Given the following post, respond as if you're commenting on Reddit:
human
Why do sunburns start to hurt after you get out of the sun? Why don’t we notice the pain while we are in the sunlight?
gpt
It’s because the burn is caused by cells dying in response to DNA damage from the sun, but it takes time for the damage to be detected and apoptosis (programmed cell death) to begin. Once it does, the burn begins.