In early 1964, Rod Serling introduced us to the Twilight Zone episode"The Self-Improvement of Salvadore Ross" which showed a man who could switch physical and emotional characteristics with the people around them. After breaking his hand, he made a deal with a fellow patient at the hospital who was sick saying that he would switch the busted hand for the other patient's cold, and the other patient agreed. Later, he was upset he did it. Why did the other patient regret his deal?
From what I can tell, neither men took the "swap" especially seriously. Salvadore managed to swap a broken hand (requiring months of painful recuperation, even for a younger man) for a minor head cold that'll take he'll only take a few days to shake off.
"I wanna swap back. It'll never heal, not at my age"
Note that when we see Salvatore a few days later, he's totally recovered and ready to make a swap with the millionaire.