The US Center for Disease Control has published some advice for those traveling to the London Olympics. The advice includes:
Make sure you are up to date on your routine vaccines, including measles. In 2011, some U.S. residents who traveled abroad got measles. When they returned to the U.S. they caused 17 measles outbreaks in various communities. To read more about measles in Europe see, the measles outbreak notice.
Learn how to access medical and emergency care in London, before you go. In the event of a serious illness or injury call 999, not 911. For minor illnesses and injuries, visit a pharmacy or walk-in center –no appointment is necessary.
Look right, look left, and look right again to avoid stepping into the path of traffic. In England, people drive on the left side of the road, not the right. Your safety is important. Road traffic is one of the leading causes of injury death to U.S. travelers in foreign countries.
For more details see the CDC Newsroom