Funny. I have a couple.
Bob and Steve are working in a saw mill. One day, Steve accidentally cuts off his arm. Alarmed, Bob puts the arm in a plastic bag and brings it to the hospital. After a couple of hours of surgery, the doctor reports it was successful and Steve is as good as new.
The next day, Steve manages to cut off his leg. Once again, Bob puts the leg in a plastic bag and takes him to the hospital, and again, the doctor reports the surgery as a success.
The day after that, Steve somehow cuts off his head. Like the previous times, Bob puts the body part in a plastic bag and brings it and Steve to the hospital. But this time, however, the doctor sadly reports that Steve didn't make it. He said that he suffocated in the plastic bag.