Charlie (Fallout 2)

Charlie is the unfortunate denizen of Vault City's Courtyard who drank unfiltered water from the well. As a result, he contracted heavy radiation poisoning and ended up in agony, crumpled on his tent's floor.

You can use your Doctor skill on him to determine that he is suffering from radiation poisoning, for which you get 100 XP. You can save him by injecting with a dose of RadAway for another 100 XP. When he stands up and thanks you, you get another 100 XP.