Subfebrile temperature in infants

Subfebrile temperature in infants: Observe or act?

Subfebrile temperature is defined as a body temperature ranging from 37.0°C to 38.0°C. For an adult this is often a sign of mild malaise, but in infants this condition has its own specifics and does not always indicate illness. It is important to interpret this symptom correctly and understand when it requires only observation and when it calls for a doctor's consultation.

Causes of subfebrile temperature

Infants have an immature thermoregulation system, so their temperature can easily fluctuate under external influences.

• Overheating. This is the most common cause. Too warm clothing, a hot room, or prolonged exposure to the sun can easily raise a child's body temperature to 37.5°C.
• After crying or activity. Intense crying or active movements also temporarily increase the temperature.
• Teething. Inflammatory process in the gums can cause a mild, subfebrile temperature rise. However, it is important to remember that teething does not cause fever above 38.0°C.
• Reaction to vaccination. After a shot, subfebrile temperature is a normal immune response.
• Onset of an infectious disease. Subfebrility can be the first, initial symptom of a URI or another infection, after which the temperature may rise higher.

Action plan for parents

If you measured the temperature and saw 37.5°C on the thermometer, first assess the overall condition of the child. If the baby is active, feeding well and playing, there is no need to panic. Your steps:

1. Eliminate possible overheating. Undress the child, ventilate the room, offer water (if the child is older than 6 months) or more frequently apply a cool compress to the chest. After 30–40 minutes, remeasure the temperature.
2. Observe. Monitor the temperature trend and the appearance of other symptoms such as runny nose, cough or rash.

Subfebrile temperature does not require the use of antipyretics. Consult a doctor if subfebrility persists for more than 2–3 days, or if other concerning symptoms appear. Read about general rules for lowering temperature in our blog.