The Food and Drug Administration (FDA) has granted 510(k) clearance to Radius Tº™, a wearable, wireless thermometer to measure body temperature continuously and noninvasively for both prescription and over-the-counter (OTC) use in individuals 5 years of age and older.

Radius Tº is designed to measure body temperature around the clock with an accuracy of ±0.18°F in the range of 77°F to 109.4°F. The wireless thermometer is a water-resistant sensor that is applied on the upper chest below the left collarbone. Each sensor has an 8-day battery life. 

Body temperature data captured by Radius Tº is transmitted through Bluetooth® connectivity to a Masimo patient monitoring or telehealth solution, or through the Masimo Radius Tº smartphone app. For use in the hospital, Radius Tº is compatible with both the Root® Patient Monitoring and Connectivity Hub and the Rad-97® patient monitor, as part of the Masimo Hospital Automation™ platform. 

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Radius Tº is available as a 3-pack sensor for use in hospitals and at home. The Masimo Radius Tº app is available for iOS and Android devices.

Joe Kiani, Founder and CEO of Masimo, said, “Radius Tº was first made available in the US under an FDA COVID-19 enforcement policy for thermometers as part of Masimo SafetyNet – where it quickly demonstrated its value in improving clinician workflows through its continuous, remotely accessible body temperature measurements for patients recovering or quarantined at home. Now, with the FDA 510(k) clearance, the availability of the Radius Tº is being expanded for use by both clinicians and consumers to help monitor and track body temperatures in all thermometer applications.”


  1. Masimo announces FDA 510(k) clearance of Radius Tº™ for prescription and over-the-counter (OTC) use. [press release]. Irvine, CA: Masimo; June 21, 2021. 
  2. Masimo. Radius Tº™. Accessed June 21, 2021.

This article originally appeared on MPR