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URL of this page: //medlineplus.gov/ency/imagepages/19700.htm
Thermometer temperature
Overview
Fever is an important part of the body's defense against infection. Most bacteria and viruses that cause infections in humans thrive best at 98.6°F (37°C). Raising the body temperature a few degrees can help the body fight the infection. In addition, a fever activates the body's immune system to make more white blood cells, antibodies, and other infection-fighting agents.
Review Date 5/18/2026
Updated by: Sandeep K. Dhaliwal, MD, board-certified in Diabetes, Endocrinology, and Metabolism, Springfield, VA. Also reviewed by David C. Dugdale, MD, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.
