Two guys are working at a sawmill when—WHAM!—one of them gets too close to the blade and chops off his arm. His buddy grabs the severed limb, shoves it in a plastic bag, and rushes him to the hospital.
The next day, he visits his friend and finds him casually playing tennis.
“Incredible!” he says. “Medical science is amazing!”
A month later, same sawmill, same two guys—WHAM!—this time, the poor guy’s leg gets lopped off. Once again, his buddy scoops it up, bags it, and hauls him to the hospital.
The next day, he stops by to check in and finds his pal outside playing football.

“Incredible!” he says. “Medical science is amazing!”
Another month goes by, and wouldn’t you know it—WHAM!—this time, the guy bends too close, and off comes his head. His buddy sighs, shoves it in a plastic bag, and rushes to the hospital one more time.
The next day, he arrives to visit his friend—but he’s nowhere to be found. He spots the doctor and asks, “Hey, Doc, where’s my friend? I brought him in yesterday.”
The doctor shakes his head. “Oh yeah… some idiot put his head in a plastic bag, and he suffocated.”