Fever, acute diseases[colds, flu, sore throats, upset stomach etc.] in children older than 9 months, always count the breathing for a full minute while asleep [see former articles about breathing frequency]

You may ask a health food shop of herbal pharmacy to  combine the following herbs for you:

Achillea mill / Sambucas / Mentha pip. / Tilia , equal parts of each [for example 30 gram of each] and to add Chamomile /Melissa /Catnip[=nepata cataria] 15 gram of each.

To be mixed all together. Take a full table spoon of the mixture and make a tea[to be covered for some 15 minutes], strain and give often little bits to drink . NO acamol [paracetamol] or even worse Nurofen[ibuprofen]!