Greg Barnum, of Mobilio & Sons Heating & Cooling, spent Tuesday working on the roof of a building in downtown Bridgeport, where the feels-like temperatures soared well over 110 degrees. "We're actually used to that because when we work in people's attics during the summer, the feels-like temps easily climb up to 130 degrees, believe it or not," Barnum told News 12. Barnum was among many HVAC workers across the region who were forced to battle the heat despite the dangers, as overworked AC systems strain to keep up with high demand during the first heat wave of summer "We follow all the basic rules -- keeping hydrated, pacing ourselves, etc," Barnum said. "It's the profession we chose and we actually enjoy the challenge," he said. Barnum said all HVAC companies are seeing a surge in service calls. "Don't give up if you can't connect immediately with an HVAC company - because persistence is key to getting an appointment," he said.