Mark Darrow, a meteorologist at the National Weather Service's Storm Prediction Center in Norman, Okla., keeps watch by looking for evidence of tornadoes, heavy winds and damaging hail.
Sue Ogrocki/AP
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Hand washing at California's Pacific Hospital, especially in the ICU, is now so routine that nurses complain their hands are chapped.
Leah-Anne Thompson/iStockphoto.com
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