President John F. Kennedy is the only U.S. president with a Purple Heart. Kennedy, who served in the Navy during World War II, injured his back when a Japanese destroyer collided with his patrol torpedo boat near the Solomon Islands. As his boat sank, Kennedy refused to let his injury stop him from towing a badly burned crew member to safety. Kennedy swam with the man’s life jacket strap clenched between his teeth for three miles before reaching an island and bringing the man safely to shore. Kennedy was also awarded the Navy and Marine Corps Medal for his actions.

Source: United Service Organizations