Cold & Flu Symptoms What Is Normal Body Temperature? Body temperature is regulated by the hypothalamus By Carisa Brewster Carisa Brewster LinkedIn Twitter Carisa D. Brewster is a freelance journalist with over 20 years of experience writing for newspapers, magazines, and digital publications. She specializes in science and healthcare content. Learn about our editorial process Updated on April 21, 2022 Medically reviewed Verywell Health articles are reviewed by board-certified physicians and healthcare professionals. These medical reviewers confirm the content is thorough and accurate, reflecting the latest evidence-based research. Content is reviewed before publication and upon substantial updates. Learn more. by Chris Vincent, MD Medically reviewed by Chris Vincent, MD LinkedIn Chris Vincent, MD, is board-certified in family medicine. He is a clinical professor at the University of Washington School of Medicine and practices at Harborview Medical Center in Seattle. Learn about our Medical Expert Board Print A normal body temperature is best described as a range. The standard range is generally considered to be between 97 and 99 degrees Fahrenheit. Each individual might be slightly below or above this range. Body temperature is regulated by the hypothalamus, located at the base of the brain. Measuring Body Temperature Mercury-filled glass thermometers used to be the norm for measuring body temperature, but due to mercury’s toxicity, healthcare professionals recommend using digital thermometers. Grace Cary / Moment / Getty Images There are a few ways to take your temperature: oral, rectal, or axillary. The digital reading will vary slightly depending on which method you use. A rectal temperature is taken by inserting a thermometer into the rectum. This method is typically used in children from infancy to 3 years of age. A rectal temperature below 100.4 degrees Fahrenheit is normal. Oral temperatures are taken by mouth. This method is common for adults and children 3 years and older, provided they can hold the thermometer securely under their tongue. An oral temperature below 100 degrees Fahrenheit is normal. The axillary method is taken under the armpit. However, the reading is not as accurate, so should be followed up with an oral or rectal reading if fever is suspected. An axillary temperature below 99 degrees Fahrenheit is normal. Other methods include forehead (temporal artery) and ear (tympanic) thermometers. The Right Way to Use a Thermometer Conditions Affecting Body Temperature Health conditions, environmental factors, and biological processes can cause body temperature to fluctuate. For instance, hormone changes during the female menstrual cycle can cause body temperature to rise. But certain situations can cause temperature changes that can pose health risks. They include: Fever: A body temperature of 100.4 degrees Fahrenheit or more is considered a fever. This increase is usually in response to harmful viruses or bacteria invading the body. Heatstroke: This occurs when environmental conditions are extremely hot or humid. Sweat does not evaporate as quickly off the skin, causing the body to overheat. Core body temperature can reach levels as high as 106 degrees Fahrenheit. Hyperthyroidism: This is a condition where your body releases too much thyroid hormone. This causes your metabolism to speed up and one of the symptoms is an increase in body temperature and perspiration. Hypothermia: This happens when your body temperature goes below 95 degrees Fahrenheit. Hypothermia is caused by prolonged exposure to cold temperatures. Hypothyroidism: This is a condition where your body produces too little thyroid hormone. Your metabolism slows down too much and it becomes difficult to stay warm. During a hot flash, a person has a feeling of severe heat, usually across the face, neck, and upper body. Typically, hot flashes occur during the onset of menopause in people who menstruate. While a hot flash can feel intensely uncomfortable, it is the skin that is heated. It does not increase your core body temperature above normal. A Word From Verywell It can be easy to get preoccupied with data readings and worry if a number is a sign that something is wrong with your health. But not only does a normal body temperature vary throughout the day and from person to person, it can change for a population over time. A study published in 2020 has shown that the average body temperature in the United States has actually decreased since the Industrial Revolution. With the exception of specific health conditions, your core body temperature will remain stable and within the normal range. Even a fever is not usually cause for immediate concern. But if your temperature is 103 degrees Fahrenheit or higher, call your healthcare provider. 13 Reasons Why You’re Cold All the Time Was this page helpful? Thanks for your feedback! Looking to avoid getting the flu? Our free guide has everything you need to stay healthy this season. Sign up and get yours today. Sign Up You're in! Thank you, {{form.email}}, for signing up. There was an error. Please try again. What are your concerns? Other Inaccurate Hard to Understand Submit 8 Sources Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy. Cleveland Clinic. Body temperature: What is and isn't normal. Institute for Quality and Efficiency in Health Care (IQWiG). How is body temperature regulated and what is fever? InformedHealth.org. Updated November 17, 2016. Cleveland Clinic. Thermometers: How to take your temperature. MedlinePlus. Temperature measurement. Michigan Medicine. Body temperature. Molnar GW. Body temperatures during menopausal hot flashes. J Appl Physiol. 1975;38(3):499-503. doi:10.1152/jappl.1975.38.3.499 Protsiv M, Ley C, Lankester J, Hastie T, Parsonnet J. Decreasing human body temperature in the United States since the industrial revolution. Elife. 2020;9:e49555. Published 2020 Jan 7. doi:10.7554/eLife.49555 MedlinePlus. Fever.