Administering acetaminophen or ibuprofen reduces an adult fever, according to eMedicineHealth. Allowing the person to take a cool bath or placing cool cloths on his body brings down a fever as well. Drinking cool fluids decrease body temperatures and provide hydration.
An adult with a temperature below 102 F only needs to rest and drink lots of fluids, advises Mayo Clinic. If his temperature rises above 102 F and he is uncomfortable, acetaminophen or ibuprofen can help. Medical attention is in order if the fever consistently remains above 103 F, the fever does not decrease despite administration of medication, the fever persists for three days or more, or the individual has other unusual symptoms, such as a severe headache, shortness of breath or a stiff neck.