"It's much hotter these days," said a 63-year-old worker, who has worked in the industry for 40 years. "I suffer from heat illness every year, though it's been mild enough." […] "Summer beats me the most," said an 81-year-old traffic guard at the site. He missed the morning meeting that day because he had been so exhausted from his work the day before. Over a third of the nation's construction workers are now over 55, a trend shared by the firm, and the share of older workers in the industry is growing.