Almost every evening my neck and sometimes my face get very hot and sensitive and my body temp gets somewhat elevated 98.8-99.3. what could cause this?

FUO: If your symptoms have been occurring for a few weeks, this meets the criterion for fever of unknown origin. Possibilities include various infections or malignancies such as lymphoma. Hyperthyroidism must also be considered. An infectious disease specialist or rheumatologist is best qualified to evaluate you. Appropriate tests will be ordered after a thorough history and physical examination.