Science: Misery Begins at 70

After years of listening to the lament "It isn't the heat, it's the humidity," the U.S. Weather Bureau has finally decided to warn—or at least try to warn—people when a particularly sticky day is in the offing. By the time next summer's heat and humidity come along, the forecaster will have a "discomfort index" that combines both the air's temperature and the amount of moisture in it. Under the formula, explains Climatologist Earl C. Thorn, a discomfort figure of 75 might mean 80° temperature and 60% relative humidity, or it could mean 85° temperature and 30% relative humidity, or 75° temperature, 100% humidity. All are unpleasant. Thorn estimates that 10% of the population can expect to feel uncomfortable before the index reaches 70. When it reaches 75, half the people are uncomfortable. At the index of 79, everybody is uncomfortable.