--- title: "Heat Stress in Outdoor Sports Events a Growing Concern" url: https://newscentral.site/heat-stress-in-outdoor-sports-events-a-growing-concern/ language: en publisher: "News Central Site" section: "Science" published: 2026-10-21T11:40:04.000Z updated: 2026-10-21T14:43:10.666Z id: d5aaebd3-8d28-4ae1-a2e6-943a14b14d46 source: "Phys.org https://phys.org/news/2026-10-smart-outdoor-sports-tournaments-environmental.html" attribution: "Link to https://newscentral.site/heat-stress-in-outdoor-sports-events-a-growing-concern/ and name News Central Site when you quote or summarize this story." --- # Heat Stress in Outdoor Sports Events a Growing Concern Rising temperatures caused by climate change are posing a significant challenge for organizers of outdoor sports events worldwide. The heat not only affects athletes' performance but also increases their risk of suffering from heatstroke, a leading cause of nontraumatic death among professional athletes. In Japan, where school tennis championships often take place during summer vacation, excessively hot days can be particularly problematic for event organizers. With multiple matches to complete within a tight schedule, they must carefully balance the need to protect players from heat-related illnesses with the need to ensure that the competition finishes on time. To gauge the level of heat stress on any given day, many sports organizations rely on the wet-bulb globe temperature (WBGT) index. This widely used tool takes into account air temperature, humidity, and solar radiation, providing a comprehensive assessment of the conditions under which athletes will be competing. The International Olympic Committee and numerous sports federations have adopted the WBGT as a key indicator for making decisions about whether to continue exercise in hot weather. By using this index, event organizers can make informed choices about how to protect their athletes from heat-related risks while still ensuring that competitions are completed successfully. To further assist event organizers in managing heat-related risks for athletes, a key limitation of the Wet Bulb Globe Temperature (WBGT) index has been addressed by researchers from Doshisha University in Japan. The WBGT index provides valuable information on potential heat hazards but does not offer guidance on whether it is feasible to complete a tournament under high-heat conditions. A research team led by doctoral student Hiroki Yamaguchi developed a framework for evaluating the completion of tennis tournaments in extreme weather. This study aimed to bridge the gap between heat measurements and scheduling decisions, providing event organizers with more informed choices about their planning. The researchers analyzed over 119,000 hourly WBGT readings collected across Japan from 2018 to 2022 at 11 meteorological stations. By applying the Japan Sports Association's guidelines for heatstroke prevention, they identified hours with a WBGT below 28 as "low-risk operational time." This allowed them to translate these measurements into practical tournament indicators. The team converted these low-risk operational hours into feasible tournament days and estimated the number of matches that could be completed under such conditions. By using this approach, event organizers can gain valuable insights into how to balance athlete safety with the demands of completing a tournament. To determine a safe operating schedule for outdoor sports tournaments, researchers modeled the first day of the individual tournament at the 2025 Inter-High School Athletic Meet, which would feature 180 matches across 20 courts. Assuming each match takes 30 minutes and there's a 10-minute turnaround between games, the required operating time per court was calculated to be six hours per day. The researchers then compared this with the safe operating hours determined by environmental heat measurements, known as WBGT, to calculate an operational margin. The team also analyzed different tournament schedules for July to September, using three daily scheduling models: a standard 9 a.m. to sunset format and two alternative formats that avoid the hottest part of the day. These included an early-morning schedule and a nighttime schedule. Statistical analysis revealed that adjusting playing hours had a more significant impact on ensuring low-risk operating conditions than changing tournament dates. In fact, both the nighttime and early-morning models increased the likelihood of WBGT levels remaining below 28 by substantial margins. Applying adjustments to both tournament dates and playing hours resulted in the most significant overall improvement, adding up to 0.8 extra days of low-risk playtime over a seven-day tournament period. The researchers also examined whether the analyzed schedules provided sufficient time to complete a standard benchmark tournament. While many scheduling scenarios met this requirement on average, the amount of spare time varied significantly. For instance, the July 11-20 early-morning scenario had the largest average margin at 2.2 hours per day, while the September 1-10 standard schedule fell short by an average of 0.5 hours per day. These findings indicate that merely meeting a threshold is not sufficient and that organizers should carefully consider how much extra time remains under a given schedule. This approach emphasizes the importance of evaluating available spare time in conjunction with environmental heat indices. The proposed method offers new indicators to complement existing safety guidelines by quantifying available time before an event begins, allowing decision-makers to make informed decisions about tournament planning. The proposed method aims to optimize outdoor sports tournaments by considering environmental heat measurements. This approach involves reviewing and adjusting various aspects of tournament planning, including dates, time of day, locations, number of courts, and match formats. By taking into account the operational margins and matching surplus, decision-makers can make informed decisions about tournament planning, ultimately prioritizing player safety and sustainability. The method's focus on quantifying available time before an event begins provides a crucial factor in making these decisions. The ultimate goal is to ensure that tennis tournaments are hosted safely and sustainably, minimizing risks to players while promoting environmentally friendly practices. By incorporating environmental heat measurements into tournament planning, organizers can create a safer and more responsible experience for all involved. --- Source: [Phys.org](https://phys.org/news/2026-10-smart-outdoor-sports-tournaments-environmental.html) Published by News Central Site: https://newscentral.site/heat-stress-in-outdoor-sports-events-a-growing-concern/