A warm welcome to HCM
This is actually the time, when most of the fever
and associated chills
are of viral origin.
How ever chances of tropical diseases like malaria
cannot be avoided, particularly if you are residing in or your husband had travelled to an endemic zone in the recent past.
Let him get investigated for malaria. If turned out to be negative then most probably he will be fine within few days with supportive treatment. Give him plenty of water to drink with added electrolytes.
You need to give him paracetamol
instead of only ibuprofen
wishing a speedy recovery.