According to a sibling comment the abstract claims "a mean absolute error of 0.229 °C". According to wiki the normal temperature window is 36.5–37.5 °C and that of a fever is 37.2-37.7 °C or higher, with variations for both of about 0.5 °C throughout a 24 hour period.

> An early morning temperature higher than 37.2 °C (99.0 °F) or a late afternoon temperature higher than 37.7 °C (99.9 °F) is normally considered a fever, assuming that the temperature is elevated due to a change in the hypothalamus's setpoint.[14] Lower thresholds are sometimes appropriate for elderly people.[14] The normal daily temperature variation is typically 0.5 °C (0.90 °F), but can be greater among people recovering from a fever.

https://en.wikipedia.org/wiki/Human_body_temperature