Some times there could be a situation in which the person is having dizziness, fever and some infection, e.g throat infection. The cause of dizziness might be considered to be low blood pressure by some physicians, but it is not usually so.
The dizziness is probably due to the fever and is mostly seen in children and teenagers. Although checking the blood pressure is a good step in the examination of the patient, but its equally important to lower down their fever.
First of all remove all extra clothing from the patient. What should he/she wear? exactly what you are wearing yourself. If you are not wearing a high neck, then don’t ask them to do too, if you are not wearing socks and gloves, then ask them to remove them too.
Give them antipyritics according to their age and donot make them sit directly in front of the heater.
Other than that, resolve the infection by using the antibiotics necessary.