Benjamin Franklin had a habit of engaging in a daily “air bath.” He regarded this as a novel method to avoid cold, flu, and even smallpox. He wrote in 1768: “I have found it . . . agreeable to my constitution to bathe in another element. I mean cold air.”

Ben would arise every morning, and sit in his chamber without any clothes on whatever. He would throw open the room’s windows, even in cold weather, and enjoy the fresh air for a half hour or even an hour, depending on the season. During this time he would either read or write.

“This practice,” he said, “is not in the lease painful, but on the contrary, agreeable.” He considered it one reason he seldom suffered from colds or influenza.

Ben frequently recommended this practice to other people, but his advice seemed to fall on deaf ears. It was one of the reasons, though, that others, such as John Adams and Thomas Jefferson would seldom travel with or share a room with Doctor Franklin.