A crew of electricians is perched on a rooftop at 10 am, the sun bright enough to make the metal conduit glint. Their hi‑vis vests are a plain fluorescent yellow‑green, no reflective tape, no extra bells‑and‑whistles. By lunch‑time the temperature has risen, the shadows lengthen and the site shifts to night‑shift work. Suddenly the same vests […]