When you’re camping, it’s tempting to drink water straight from pristine-looking lakes and streams — but don’t do it! A microscopic, single-celled parasite called Giardia (gee-ar-dee-ah) is the cause of a common waterborne illness known as giardiasis (gee-ar-dye-a-sis) or "beaver fever." The symptoms are diarrhea, belching, gas and cramps that first show up about one to two weeks after becoming infected, and can last four to six weeks.

To prevent giardiasis infection:

• Use bottled water only, or boil water at least one minute before using it. Alternatively, you can purify water with iodine tablets or special water filters.
• Don’t brush your teeth, wash dishes, fruits or vegetables, or use ice cubes made with water that hasn’t been purified.
• Peel raw fruits and vegetables before you eat them.
• Wash your hands with bottled or purified water only, and do it carefully several times a day.
• Don’t swallow water when you’re swimming — even in a chlorinated swimming pool (chlorine doesn’t kill all germs).

If you think you have giardiasis, see your doctor right away. You may need to give stool samples to see if you have the parasite, and then get treated with prescription drugs to get rid of it for good.