Health monitoring

For three weeks in July, the world’s most elite bike racers climb steep mountains and sprint along historic cobblestones to capture the coveted yellow jersey or the race leader in the Tour de France. It’s a 21-day feat of human endurance that requires constant eating and drinking to manage the average daily energy demand of about 6,000 calories, equivalent to around 12 McDonald’s Happy Meals, and just over 1.5 gallons of water. Nearly 5,000 miles away in the mountains of North America, radios crackle with chatter from a wildfire incident command post, air operations and other crews fighting a wildfire. Up the fireline, the swings of Pulaskis, axlike hand tools, are carving a fuel break into the land. The weather forecast predicts a high of nearly 100 degrees Fahrenheit (38 C) with wind, a combination that can push the fire high up into the canopy of dense lodgepole pines on the mountainside. The yellow jerseys here are sooty, sweat-stained and flame-resistant...