Body Temperature Guide

Temperature Scale

Hypo
Normal
Low Fever
Fever
High Fever
Status °C °F Action
Hypothermia<35.0<95.0Emergency medical care
Low (below normal)35.0–36.195.0–97.0Monitor, stay warm
Normal36.1–37.297.0–99.0No action needed
Low-grade fever37.3–38.099.1–100.4Rest, fluids, monitor
Fever38.1–39.0100.5–102.2Antipyretics, hydration, see doctor if persistent
High fever39.1–40.0102.3–104.0See doctor
Very high / Dangerous>40.0>104.0Emergency — seek immediate care

Normal Range by Measurement Site

Site Normal Range (°C) Normal Range (°F) Accuracy
Rectal (most accurate)36.6–38.097.9–100.4★★★★★
Ear (tympanic)35.8–38.096.4–100.4★★★★☆
Oral (under tongue)35.5–37.595.9–99.5★★★★☆
Axillary (armpit)34.7–37.394.5–99.1★★★☆☆
Forehead (temporal)35.4–37.495.7–99.3★★★☆☆

Temperature Converter

Fever Thresholds by Age

Age Fever Threshold Notes
0–3 months≥38.0°C / 100.4°FGo to ER immediately
3–12 months≥38.0°C / 100.4°FCall doctor if >2 days
1–3 years≥38.5°C / 101.3°FSee doctor if >3 days or >40°C
3–17 years≥38.5°C / 101.3°FMonitor, see doctor if persistent
Adults≥38.3°C / 100.9°FSee doctor if >3 days or >39.4°C
Elderly (65+)≥37.8°C / 100.0°FLower threshold; monitor closely