It's because Satan isn't punishing them. Hell is where people are separated from God. Satan is a fallen angel who betrayed God, who is also being punished. Satan isn't God and doesn't send but drags people to hell with him
The blood thing is literally the reason I first donated. The lady was like "Save three lives everytime!" but I heard "have three people owe you their life forever:. Because I am insane.<< Well, here's another way to look at donating blood.