When a FIFA World Cup match gets dangerously hot, doctors and cooling stations are deployed in an instant. But a Sunday league player facing those same conditions often has only a coach making a judgment call on a hot afternoon. The Sports Heat Tool, developed at the University of Sydney, is closing that gap—one free download at a time.
The interactive online tool, available on Apple App Store and online, calculates sport-specific heat risk for over 33 activities—from soccer and softball to canoeing and cycling—empowering anyone, anywhere, to make evidence-based decisions about whether it's safe to play. As temperatures soar across the Northern Hemisphere this summer, the timing could hardly be more relevant.
Professor Ollie Jay, director of the Heat and Health Research Centre at the University of Sydney, helped develop the tool with a simple mission: put the science that protects elite athletes into everyone's pocket. "A local club has a coach, a hot afternoon and a judgment call," Jay said. "We have taken the science that the professionals rely on and put it in everyone's pocket for free. Your body follows the same rules whether you are playing at a FIFA World Cup or a Sunday league."
The tool asks users to enter their location and choose their sport, then returns a heat-risk score ranging from 1.0 (low) through to 5.0 (extreme) for the hours and days ahead—alongside practical steps to bring the risk down. What sets it apart from older indices, according to Dr. Federico Tartarini, who co-developed the tool with Jay, is that it models how a real human body actually exchanges heat with its surroundings. It accounts not just for temperature, but for humidity, sun exposure, and the exertion level of the activity itself—so the risk it shows is the risk you're genuinely facing.
The need is real. Most people judge heat by how it feels, but two days at the same temperature can carry very different dangers depending on the conditions. The tool gives people around the world a concrete, sport-specific answer to a question millions ask each summer: Is it too hot to play?
Looking ahead, the team plans to launch a version tailored specifically for children and adolescents later this year—a group whose bodies manage heat differently from adults and are particularly vulnerable in extreme conditions. It's a step toward ensuring that no player, regardless of age or resources, has to guess their way through a dangerous heatwave.