What temperature is a fever?

For adults: oral temperature above 100.4°F (38°C). For children: rectal temperature above 100.4°F. Temporal and ear readings may be 0.5-1°F lower than rectal. A 99°F temporal reading could correspond to 100°F rectal. Smart thermometer apps often adjust for measurement location. When in doubt, consult your pediatrician's guidance.

Are no-contact thermometers accurate?

Quality no-contact temporal thermometers (Withings Thermo) are accurate within 0.4°F of rectal temperature. Cheap no-contact thermometers can vary by 1-2°F. Accuracy is affected by sweating, ambient temperature, and technique. The Withings 16-sensor design compensates for these factors better than single-sensor models.

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