U.S. health officials say people traveling to the Summer Olympic Games should see a healthcare provider four to six weeks before leaving for London. Millions of international visitors will travel to London this summer for the 2012 Summer Olympic and Paralympic Games and, in many ways, travel to and throughout Britain is similar to travel in the United States -- but the expected crowds might increase risk of illness and injury, U.S. Centers for Disease Control and Prevention officials said. \"Visit your healthcare provider four to six weeks before your departure date and get up-to-date on routine vaccines, especially measles. There\'s a large measles outbreak in Europe, and a lot of unvaccinated American travelers got sick last year,\" CDC officials said. \"Also be sure to contact your health insurance provider to learn the extent of your medical coverage and consider purchasing travel health insurance if necessary. Pack a travel-health kit that includes medicines you take regularly, along with fever and pain relief pills.\" While in England, follow these prevention actions: -- Wash your hands often with soap and water or an alcohol-based hand sanitizer. -- Drink alcohol in moderation, avoid drinking and driving and use latex condoms if having sex. -- Stay alert, especially in crowds. -- Be careful crossing the street, wear a helmet if riding a bike or motorcycle, use a seatbelt if traveling by car, and remember that Londoners drive on the left, the opposite side of the road. -- If sick abroad, notify your healthcare provider when you return.