Michael Shields has serviced swimming pools in the Phoenix area for years, enough time to hone a strategy for surviving the brutal heat that descends on this Arizona desert city every summer. He typically rises at 4 a.m., covers himself in protective clothing, loads up on electrolyte drinks and drenches his hands and face in sunscreen. Ready to face the inferno, he arrives at his first customer's home well before dawn, when the temperature is already in the mid-90s Fahrenheit. There are days when the mercury climbs to well over 100 degrees Fahrenheit (38 degrees Celsius) in the summer here. But over the past two weeks, the mercury has hit 110 degrees F (43 C...Keep on reading: Summer-tested Phoenix braves relentless wave of extreme heat