Risks of Low Body Temperature - Causes of Hypothermia and Its Impact on Immunity

What Is Low Body Temperature

Normal human body temperature is generally considered to be 36.5 to 37.0 degrees Celsius, and a baseline below 36.0 degrees is sometimes called low body temperature. While not a formally defined medical condition, chronically low body temperature affects immune function, metabolism, and circulation, and is said to contribute to various health issues.

Body temperature is maintained by multiple systems including heat production by muscles, blood vessel constriction and dilation controlled by the autonomic nervous system, and metabolic regulation by thyroid hormones. Problems with any of these can lead to chronically low body temperature.

Low body temperature often lacks obvious symptoms, and it is easy to dismiss it as simply one's natural constitution. However, low body temperature is one clue for reviewing how the body is working.

How Low Body Temperature Affects Immunity

Body temperature and immune function are said to be related. Immune cells (white blood cells, NK cells, etc.) are thought to be more active at higher body temperatures. Fever during a cold is one of the body's responses that raises temperature to support immune cell activity.

People with low body temperature may feel that they catch colds easily or recover slowly. Additionally, low temperature is thought to impair blood flow, making it harder for immune cells to reach every corner of the body. Daily temperature management also helps maintain immune function.

Furthermore, decreased body temperature affects enzyme activity. The body's enzymes are said to work well near body temperature, and when temperature drops, metabolic reactions slow down. This can be the cause of vague feelings of being "not quite right."

Muscle Mass Decline and Low Body Temperature

Muscles are one of the main sources of body heat. People with low muscle mass cannot generate sufficient heat, making them prone to low body temperature. Women tend toward low body temperature because they generally have less muscle mass than men.

Sedentary desk-work lifestyles, lack of exercise, and muscle loss from excessive dieting are factors in low body temperature. Age-related natural muscle loss (sarcopenia) also contributes. To maintain and increase muscle mass, lower-body exercises like squats and walking are effective. The lower body has large muscles, which makes it easier to boost heat production.

Strength training 2 to 3 times per week for 20 to 30 minutes per session is a guideline. Starting with bodyweight exercises like squats, lunges, and calf raises requires no special equipment. With consistency, basal metabolism increases, and resting body temperature is expected to rise.

Autonomic Nervous System Imbalance and Temperature Regulation

The autonomic nervous system is involved in temperature regulation. The sympathetic nervous system constricts blood vessels to prevent heat loss, while the parasympathetic nervous system dilates them to release heat. When this balance is disrupted, temperature regulation falters.

Chronic stress, irregular lifestyle rhythms, and sleep deprivation are factors in autonomic nervous system imbalance. Summer is particularly taxing on the autonomic system when frequently moving between air-conditioned indoors and hot outdoors. Regular lifestyle rhythms, moderate exercise, and hot-cold stimulation through bathing can help restore autonomic balance.

Activities that activate the parasympathetic nervous system, such as deep breathing and yoga, also aid autonomic balance recovery. Slow abdominal breathing for 10 minutes before bed shifts dominance to the parasympathetic system, dilating peripheral blood vessels, which may ease cold hands and feet.

Raising Body Temperature Through Diet

Diet is also one way to raise body temperature. Eating triggers diet-induced thermogenesis (DIT), which raises body temperature. DIT is highest for protein, at an estimated 20 to 30 percent of ingested energy. Carbohydrates are reported at 5 to 10 percent and fats at 0 to 3 percent (Westerterp, 2004). Skipping breakfast makes it difficult for morning body temperature to rise, so eating a protein-containing breakfast is also one way to address low body temperature.

Foods known to warm the body include ginger, green onions, garlic, chili peppers, and cinnamon. Shogaol in ginger is said to support circulation and warm the body. Conversely, excessive consumption of cold drinks and raw vegetables tends to cool the body, so those with low body temperature should favor warm cooking methods.

Bathing and Body Temperature

Soaking in a bathtub is one simple way to raise body temperature. Soaking in lukewarm water (38 to 40 degrees) for 15 to 20 minutes raises core body temperature. The gradual decline in core temperature after bathing is said to bring on natural sleepiness.

For severe cold sensitivity, foot baths are another option. Soak feet up to the ankles in slightly hot water (about 42 degrees) for approximately 15 minutes. Blood vessels in the feet dilate, supporting circulation throughout the body. Those who struggle with cold can expect constitutional improvement by making daily warming practices a habit.

Carbonated bath additives are said to dilate blood vessels and help warm the body. For those without a bathing habit, starting with 3 times per week and gradually increasing frequency is recommended.

Do Not Ignore Low Body Temperature

Low body temperature tends to be dismissed as "just my constitution," but it can lead to weakened immunity, sluggish basal metabolism, and worsening cold sensitivity. Raising body temperature means boosting overall bodily function.

Start by making morning temperature measurement a habit to understand your baseline. By reviewing lifestyle habits around the three pillars of exercise, diet, and bathing, body temperature can be expected to rise little by little. As body temperature stabilizes, some people notice changes like catching fewer colds and feeling less fatigued.

Temperature improvement takes time. As body temperature rises, basal metabolism may also improve. Improving low body temperature relates to various aspects of health - immunity, metabolism, beauty, and mental health. As a small first step you can take today, start with morning temperature measurement and a warm breakfast.