Hi,
Welcome to health care magic,
I have read your query and understand the concern.
Your husband's fever,headache and nausea with back pain are mostly related to viral infection which needs some medical attention.
Meanwhile,you can continue with symptomatic treatment like
paracetamol or advil (
ibuprofen which you are already giving him) with antihistamines like levocetrizine if there is cold or cough,cold sponging to reduce fever.
If he feels better with this symptomatic treatment and if fever is also subsiding then one can continue with that for another couple of days.
You can also add antacids (
pantoprazole 40 mg) and tab.ondasetron 8 mg for symptomatic relief.Drink plenty of fluids and fruit juices to avoid
dehydration.
Or in case,if fever is persistent with
severe back pain then it would be advisable to seek medical attention to some local doctor or GP who will take complete medical history with some relevant investigations to make a clear diagnosis.
Hope this helps.
Regards,