Skin, Temperature & Environmental

Fever is the oldest vital sign humans have measured, yet most households still rely on technology that has barely changed in a century. A connected thermometer asks whether temperature data, tracked over time and across family members, can become health intelligence rather than a single anxious reading. Body temperature is arguably the most fundamental biomarker…

Radon is the second leading cause of lung cancer in the United States. It is colorless, odorless, and present in roughly one in fifteen American homes at levels the EPA considers dangerous. Most people have never tested for it. The Environmental Protection Agency estimates that radon causes approximately 21,000 lung cancer deaths per year in…

The air outside your window and the air inside your home tell different stories about your health. Most monitors can only read one of them. In 2021, the World Health Organization revised its air quality guidelines downward, recommending annual average PM2.5 exposure below 5 micrograms per cubic meter, a threshold that approximately 99% of the…

You spend roughly 90% of your life indoors, breathing air you cannot see and rarely measure. The pollutants in that air may be quietly accelerating the very diseases you are trying to prevent. A 2024 systematic review published in Clinical Interventions in Aging by Ndlovu et al., analyzing 38 studies on indoor air pollution and…

Professional sports teams have spent thousands testing athletes’ sweat composition in labs. A $25 patch and your phone camera now approximate the same insight. For decades, the most sophisticated sweat testing available to athletes required a visit to a sports science laboratory: adhesive collection patches, centrifuged samples, ion chromatography analysis, and a results report delivered…

Dehydration degrades athletic performance before you feel thirsty, and sweat composition varies so widely between individuals that generic hydration advice may be worse than none at all. A growing body of exercise physiology research has established that even mild dehydration, a 2% reduction in body mass from fluid loss, impairs endurance performance, increases perceived exertion,…

The smallest wearable UV sensor ever made fits on your thumbnail, has no battery, and asks a question dermatology has struggled to answer: how much sun did you actually get today? Skin cancer’s relationship with ultraviolet radiation presents a paradox of modern health behavior. The science is unambiguous: UV exposure is the most preventable risk…

Your skin registers every minute of ultraviolet exposure, but your memory does not. A wearable UV sensor aims to close that dangerous perception gap. In 2019, researchers at Northwestern University published a study in PLOS ONE that exposed a troubling finding about how people perceive their own sun exposure. Alshurafa et al. equipped 39 melanoma…

Continuous overnight temperature sensing is transforming how women understand their cycles, but the science behind basal body temperature reveals both remarkable potential and persistent gaps. Every month, roughly 800 million women of reproductive age worldwide experience a hormonal cascade so precise that it shifts their core body temperature by fractions of a degree. That shift,…

A chest-strap sensor that continuously estimates core body temperature during exercise, offering athletes and military personnel a real-time window into thermoregulation that was previously available only through invasive clinical methods. Exertional heat illness kills. In the United States alone, it claims the lives of dozens of athletes and military personnel every year, and hospitalizes thousands…