Recent research has shown that the average human body temperature may be lower than the traditionally accepted 98.6°F. Studies indicate a new average closer to 97.5°F to 97.9°F, suggesting a need to reconsider what constitutes a normal body temperature. This shift has been observed over several decades and across multiple studies, including a comprehensive analysis of 20 studies between 1935 and 1999, and a large-scale study in 2023.

One study involving 96 adults over two weeks found body temperatures ranging from 95.4°F (35.2°C) to 99.3°F (37.4°C), highlighting the wide natural variation in body temperature. Therefore, knowing your own average temperature when healthy can be more informative than relying on a universal standard.

Various factors can contribute to a low body temperature, such as hypothyroidism, diabetes, liver or kidney failure, infections, endocrine dysfunctions, certain medications, and excessive alcohol or drug use. Additionally, physical attributes like low body weight can make individuals feel colder, as fat and muscle mass play roles in body insulation and heat generation.

Hypothermia, a condition where body temperature drops below 95°F (35°C), is a medical emergency. It can occur in cold as well as cool temperatures, especially if a person is wet from rain or sweat. Older adults are particularly at risk for hypothermia due to prolonged exposure to mild cold.

Body temperature also varies throughout the day, typically being higher in the afternoon than in the morning. A fever in adults is defined as a body temperature of 100.4°F (38°C) or higher, with varying levels of severity.

For more detailed information on these studies and the implications of changing body temperature norms, visit Harvard Health, Harvard Health, and Stanford News. For insights into conditions that can lead to low body temperature, check Go Ask Alice! and Harvard Health.