Miguel Vargas vividly remembers when he first understood the power of shade. He was in middle school, sprinting up and down a scrubby soccer field in Huntington Park, a small city laced with train tracks and high-voltage transmission lines just south of the Los Angeles skyline. He ran so hard in the battering sun that he overheated.
His vision went fuzzy. His heart pounded. In a daze he stumbled toward a towering red pine near the southwest corner of the field—the biggest and almost the only tree in sight.
In that shelter, Vargas’s dizziness receded. His heart rate mellowed. He returned to himself, revived by the deep, cool shadow.