By Alan Mascarenhas
The summer of 2010 was brutal for much of the Northern Hemisphere. In July, the East Coast of the U.S. sweltered to record-breaking temperatures, while in Russia, a vicious heatwave has left Moscow shrouded in fire-induced smog and residents rushing to whatever river, lake or fountain they can find. The scorching weather comes as the National Oceanic and Atmospheric Administration reports that the past decade was the planet’s warmest on record and declares global warming "undeniable." In this NEWSWEEK gallery, we look back at where the thermometer struck hardest.