Does Kinsa add 1 °F to underarm readings?

No, we do not.  Kinsa thermometers report the temperature accurately, and so a reading under the arm will be lower than an oral reading. However, our fever guidance feature takes this into account. It knows to mark a 99.4 °F (37.4 °C) underarm temperature as a low fever because it is equivalent to a 100.4 °F (38 °C) oral temperature.

The Mayo Clinic states that the following thermometer readings generally indicate a fever:

  • Rectal, ear or temporal artery temperature of 100.4 °F (38 °C) or higher
  • Oral temperature of 100 °F (37.8 °C) or higher
  • Armpit temperature of 99 °F (37.2 °C) or higher
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