For starters, before anyone freaks out, the U.S. Homeland Security threat level is actually just "Elevated" (yellow), though it's "High" for airplane flights. The threat level in NYC is "High" because we're just vigilant like that. However, freaking out over things like threat levels is apparently bad for your health, according to a new study in the Archives of General Psychiatry. Over 2700 adults were studied to " examine the degree to which acute stress......