Greenhouse gases likely accounted for over half of the widespread warmth across the continental United States in 2006, according to a new study. Last year's average temperature was the second highest since recordkeeping began in 1895. The team found that it was very unlikely that the 2006 El Niño played any role, though other natural factors likely contributed to the near-record warmth.

A nasal spray is safe and effective at rapidly treating cluster headaches, which are considered to be the most painful kind of headache with few treatment options. With cluster headaches, the pain is usually associated with neurological findings such as a droopy eyelid, small pupil, red and tearing eye, and stuffed and running nostril. All of the symptoms usually occur on the same side as the headache pain.