When your child gets a fever, it can be a stressful time for parents. Not all fevers are bad, but are a sign that your child is fighting an infection or inflammation. However, don't feel that you need to treat the fever every time - fevers help the body fight infection, and if you child seems happy and is eating and sleeping normally, then you can manage the fever with fluids, rest and observation. But if the fever is causing your child to feel unwell, have pain, loss of appetite or difficulty sleeping, then treating with Acetominophen (Tylenol or Tempra) or Ibuprofen (Advil or Motrin), can help your child feel better. And it is reasonable to manage your child at home for 1-2 days, with fever. However if the fever lasts more than 3-4 days or is above 40 degrees Celsius (104 F) at any time , then you should have your child seen by your family doctor or at a walk-in clinic. But, if your child is under the age of 3 months and has a fever, then you should seek medical attention right away, as a fever in this age group can be more serious.
What temperature is considered a fever? Good question - it depends on how you take it. The most accurate way of taking a temperature is either rectal or oral. If you take the temperature under the arm (axillary) then add 1 degree to get the actual temperature. Ear (tympanic) or forehead thermometers, although they seem easier to use, can be inaccurate if not used properly. If you are unsure if the reading is accurate, confirm it by taking a rectal or oral temperature.
FEVER is Rectal or oral temperature over 38 C (100.4 F)
FEVER is Axillary or armpit temperature over 37.4 C (99.4 F) as you add 1 degree to the Fahrenheit (F) temperature to achieve the actual temperature
Conversion from Fahrenheit to Celsius
normal body temperature: 98.6 F = 37 C
Fever (oral or rectal): over 100.4 F = 38 C
101 F = 38.3 C
102 F = 38.8 C
103 F = 39.4 C
104 F = 40 C
Medication dosing - generally we (paediatricians) dose medications based on the child's weight. Dosing for Acetaminophen is 10-15 mg per kg of body weight, to be given every 4-6 hours.
For example if your child weighs 22 lb or 10 kg , then you would give your child 100 to 150 mg of Infant or Children's Tylenol, every 4-6 hours.
Ibuprofen dose is 5-10 mg per kg of body weight, to be given every 6-8 hours.
For example, if your child weighs 22 lb or 10 kg, then you would give your child 50-100 mg of Infant or Children's Motrin or Advil every 6-8 hours.
For further information about fever in children, see the following paper by the Canadian Paediatric Society - https://www.cps.ca/en/documents/position/temperature-measurement