Heatstroke is a big concern in Japan - to such an extent that in the summer, weather reports on the news always have a section about heatstroke risk. The commonly accepted way to measure heat and, consequently the possibility of heatstroke, is the wet-bulb globe temperature (WBGT), which measures temperature in combination with humidity - and this is what the Tanita TC-210 Heatstroke Alarm does. And it does it in the most comprehensive way, allowing you to know when you have stayed in the sun too much.
The Tanita TC-210 Heatstroke Alarm uses the black bulb on its top to collect the heat from the sun and convert it to information displayed with five different indications (heat index or WBGT, temperature, relative humidity, sunburn time and date and time). It covers temperatures from 0-50°C (32-122°F) and is ±1°C (33.8°F) accurate for temperatures up to 40°C (104°F) and ±2°C (35.6°F) for temperatures higher than that. It also offers 1% accuracy for any level of humidity between 20% and 90%. Have it always with you using the hook and carabiner that come with it and stay away from danger in the summer!
The Tanita TC-210 Heatstroke Alarm features: