A prolonged heat wave has baked Las Vegas in a record fifth consecutive day of temperatures sizzling at 115 degrees or greater [Video]

Las Vegas baked Wednesday in its record fifth consecutive day of temperatures sizzling at 115 degrees Fahrenheit or greater amid a lengthening hot spell that is expected to broil much of the U.S. into the weekend.The temperature climbed to 115 shortly after 1 p.m. at Harry Reid International Airport, breaking the old mark of four consecutive days set in July 2005. And the record could be extended, or even doubled, by the weekend.Even by desert standards, the prolonged baking that Nevada’s largest city is experiencing is nearly unprecedented, with forecasters calling it “the most extreme heat wave” since the National Weather Service began keeping records in Las Vegas in 1937.Video above: Different thermometers tell different stories about the heat in Death ValleyAlready the city has broken 16 heat records since June 1, well before the official start of summer, “and we’re not even halfway through July yet,” meteorologist Morgan Stessman …