Suggest Treatment For Headache, Fever And Body Aches

HI, my daughter has been in bed since Friday with an extreme headache and high temperature, her whole body is aching. she felt slightly better yesterday morning but got worse again yesterday evening, shivering, high temperature, sweating, headache etc. she has been taking neurofen and paracetamol through out. worried as this has been going on now for over three days.

hope you can offer some advise

many thanks