What should i do when i find a homeless/drunk person sleeping on the street?

I always feel like i'm supposed to do something when i come upon a person wrapped in scavenged paper or dirty blankets sleeping on some patch of dirt or street corner. Or just sleeping on benches without cover. But i've seen others say i shouldn't bother them, let them rest, etc. If i were in their place i for sure would find it annoying if every passerby would shake me awake to check if i'm not dead yet... not doing anything either feels like i'm ignoring them.