Too hot to walk? This app knows where the shade is

For many pedestrians amid the record-breaking heat wave, every walk now begins with one question: Where’s the shade? A map app that provides the answer is gaining traction online, particularly among students and workers commuting on foot or by public transportation, as temperatures soar toward 40 degrees Celsius. The app Geuneullo: Summer Routes for Walkers calculates the position of the sun and shadows cast by buildings and street trees at a given time, then recommends the shadiest walking rout