Reducing the risk of heatstroke with TANITA
Innovation - September 8, 2025
Outdoor temperatures are increasing as a consequence of global warming and more extreme weather events. So, therefore, is the risk of heatstroke.
Heatstroke happens when the body overheats. In extreme cases, when not treated and managed quickly, it can damage the brain, heart, kidneys and muscles and lead to serious complications or death.
It’s a particular challenge in Japan, where medical experts at the Japanese Association for Acute Medicine have added a ‘most severe’ category to the existing heatstroke severity classification in response to warnings that extreme heat is straining medical services and causing damage to public health comparable to that in a “natural disaster”.
Early intervention is key.
That’s why TANITA first started to develop a WBGT (WetBulb Globe Temperature) monitoring device, an IoT-enabled WBGT meter that can relay information about outdoor temperature, humidity and solar radiation, and help decision-makers be aware of increased risk of heat injury or heatstroke.
A decade of development
TANITA is a Japanese organization based in Tokyo, and the world leader in health monitoring. However, in 2014 they introduced a new product range, a WBGT meter that could help combat heatstroke.
Since that release they have developed several different models of WBGT meters, with Saft coming on board in 2021 to examine some of the technical requirements for the latest hardware – the TC-350 model. This updated model was launched in 2024 alongside the TANITA WBGT management service, a user-friendly online platform that collates and displays data from the meters.
The new model uses a LSH20 1S2P battery pack – ideal for long-life high-capacity power source that can operate outdoors at elevated temperatures.
Images credit: TANITA
The meters and management service are designed to be used in tandem, and are particularly useful for schools, public services and parks, and businesses that rely on workers being outdoors for prolonged periods of time (e.g., construction sites).
But there is also great benefit to one-off deployments at large-scale sporting events, music festivals and marathon events where heatstroke is particularly common – often involving a lot of physical exertion in the year’s warmest months.
The 2020 Summer Olympics in Tokyo (held in 2021) was seen as the ‘hottest Olympics in history’ with athletes struggling to cope in the high temperatures. Two tennis players – Kazakhstan’s Zarina Diyas and Spain’s Paula Badosa – retired mid-match with heat exhaustion and multiple other instances of heat injury were recorded.
The TANITA solution provides a helping hand to organizers of such events.
Indeed, in April 2024’s Gifu Seiryu Half Marathon, nine TC-350 meters were deployed across the course. The heat index at each point on the course was sent in real-time to the tournament management headquarters. There, the team could check where the risk of heatstroke was highest, and quickly take countermeasures for each location.
They informed runners of the level of heatstroke risk in the form of a yellow flag (when the heat index was more than 18 and less than 22), and a red flag (when it was more than 22 or less than 28). This would act as a warning to runners to be wary of their own condition and to hydrate properly. When the heat index went above 28, the course rescue staff directly urged runners to hydrate and adjust their running pace. In addition, since the data suggested the heat index was particularly high at the finish line, the team set up a tent so finishing runners could rest and recover in the shade.
This innovative use of IoT applications is vital for combatting heatstroke and is ever-more important with temperatures continuing to rise.
While the TC-350 and management service is currently only available in Japan, its early success may lead to it being made available to a global market in the future.
