When should I treat a fever in my toddler 3 months to 3 years?

What the evidence says

Fever is your child's body fighting an infection. It is not dangerous on its own, and how high the number goes does not tell you how sick your child is. A child with a mild cold can spike a high fever, while a child with a serious infection sometimes has none at all.

Canadian guidance says you don't have to treat a fever just because it's there. Medicine like acetaminophen (Tylenol) or ibuprofen (Advil) is mainly for making your child more comfortable, easing aches, or helping them rest and drink fluids, not to force the thermometer down to normal.

If your toddler is drinking, playing a little, and generally seems okay between fever spikes, you can often just keep them comfortable with light clothing and plenty of fluids, and skip medicine altogether. If they seem miserable, achy, or can't settle, that's when medicine helps.

A few safety rules: don't give ibuprofen to a baby under 6 months old, or to any child who isn't drinking well, without checking with a doctor first. Never give aspirin to a child with a fever, it's linked to a rare but serious illness called Reye syndrome.

See a doctor if your baby is under 6 months old and has a fever, if the fever lasts more than 48 to 72 hours, or if your child looks very unwell, is hard to wake, is not drinking, or you're just worried. Trust how your child looks and acts over the number on the thermometer.