Despite extreme heat claiming more lives in the Las Vegas Valley than any weather event, officials have fallen behind in helping the region adapt, attendees of the first Southern Nevada Heat Summit said Wednesday. They pointed to what they described as a fractured approach across local governments and a lack of sustainable funding. For officials like Cheryl Nagy at the Clark County Office of Emergency Management, responding to dangerously hot temperatures has not traditionally been part of the job description. But just before the Fourth of July last year, a gusty storm knocked down miles of power lines in southeast Las Vegas, leaving about 30,000 customers without power for air conditioning in the hottest month of the year. Nagy, the office’s preparedness and recovery coordinator, got word of a senior living facility where about 150 apartments were getting hotter by the minute. County officials transported those residents to the Las Vegas Convention Center that day, saving lives.…