Recent research has indicated a shift in what is considered a normal body temperature. Initially established at 37°C (98.6°F), modern studies suggest this might be an overestimation. For instance, a Stanford research published on January 7, 2020, highlights that the average human body temperature in the United States has decreased since the 1800s.

A study involving 96 adults over two weeks revealed a wide temperature range from 35.2°C (95.4°F) to 37.4°C (99.3°F). This diversity in body temperatures underlines the importance of understanding one’s average temperature when feeling well, rather than relying on a fixed number. It appears that the average oral temperature has declined to around 97.5°F, based on an analysis of 20 studies conducted between 1935 and 1999. A similar conclusion was drawn from the 2023 study and an earlier study of more than 35,000 people, which found the average body temperature to be approximately 97.9°F.

Feeling cold can be attributed to various factors, such as low body weight, with both muscle mass and fat playing crucial roles in body heat retention. Muscle activity generates heat, while fat acts as an insulator. Those who have recently lost significant weight or have always been lean may feel colder. Additionally, skipping meals can contribute to this sensation.

Body temperature tends to be higher in the afternoon than in the morning. Fever in adults is defined as a body temperature of 100.4°F (38°C) or higher, with different levels of severity, including low-grade fevers ranging from 99.1 to 100.4°F (37.3 to 38.0°C).

Hypothermia, a medical emergency, occurs when body temperature drops below 95°F (35°C). While it is most common in very cold temperatures, it can also occur in cooler conditions (above 40°F or 4°C), especially if the person is wet from rain, sweat, or immersed in cold water.

Maintaining an internal body temperature around 98.6°F, with some variation, is crucial for optimal bodily function. Deviations from this range, whether due to exercise or exposure to extreme temperatures, can impact health.

A low body temperature, around 96 or 97 degrees, can be normal for some individuals. However, it can also indicate various health issues, such as hypothyroidism, diabetes, liver or kidney failure, infection, endocrine dysfunction, or be a side effect of certain medications. Excessive alcohol or drug use can also contribute to a lower body temperature. Anyone experiencing these conditions should seek medical advice.