You probably have been told that your body temperature "should" be 98.6 degrees Fahrenheit and that any deviation, higher or lower, is a red flag for potential health concerns. But the reality is much more complex. Generally, body temperature is somewhat variable among individuals and may fall within the range of 97 to 99 degrees Fahrenheit (36.1 to 37.2 degrees Celsius) as recorded by an oral thermometer. Other factors that affect this temperature include age, sex, time of day, and even levels of physical activity.While a slightly lower temperature might not be alarming, the possible reasons behind it should be known. Let's take a deep dive into the causes of low body temperature and when to seek medical help.What Does a Low Body Temperature Indicate?Good news: A slightly lower-than-normal body temperature is often nothing to worry about. Research from Harvard Health Publishing suggests that the "new normal" for body temperature might be closer to 97.5 degrees Fahrenheit (36.4 degrees Celsius). This shift could result from factors like increased time spent in climate-controlled environments and a population-wide reduction in metabolic activity and inflammation.That said, it is a medical emergency with a body temperature that remains consistently lower than 95 degrees Fahrenheit or 35 degrees Celsius. Hypothermia occurs if the body loses heat much faster than it can replenish it, thereby slowing down the nervous system and heart and other vital organs.Causes of Low Body Temperature1. HypothermiaExposure to prolonged cold environments may cause hypothermia. Babies and the elderly are the most vulnerable as their bodies cannot regulate temperature as effectively as other people. The symptoms include shivering, slow breathing, confusion, and drowsiness.Wear warm clothing in cold weather, and avoid excessive alcohol consumption because it increases heat loss through dilation of blood vessels. In case hypothermia has set in, go to a warm place immediately, remove wet clothes, and seek medical care.2. HypothyroidismThe thyroid gland controls metabolism, which directly relates to body temperature. An underactive thyroid, or hypothyroidism, results in a low body temperature that is persistent. Often, symptoms include fatigue, weight gain, and intolerance to cold.If you suspect a thyroid problem, see a doctor who will draw blood to determine your hormone levels. Therapy usually consists of replacement thyroid hormone therapy.Also Read: How Your Bedroom Temperature Impacts Your Sleep Health3. Nervous System DisordersThe hypothalamus in the brain controls body temperature. Conditions affecting the nervous system, such as strokes, Parkinson's disease, or multiple sclerosis, can disrupt this regulation, resulting in a low body temperature. These disorders may also impair the body's ability to respond to cold environments.4. Severe InfectionsWhile infections often cause fevers, serious illnesses like pneumonia or sepsis can cause a drop in body temperature, especially in older adults or people with weakened immune systems. Low body temperature in these cases can indicate complications that require urgent care.5. Certain MedicationsCertain antidepressant medications, drugs used for the treatment of bipolar disorder, and medications used to treat schizophrenia can result in hypothermia as a side effect. In this case, you must contact your health care provider and have him determine whether or not this is indeed due to a drug.6. Other Medical ConditionsLow body temperature may result from anorexia nervosa, deficiency of vitamin B1, hypoglycemia, or from erythrodermic psoriasis-a serious skin disease.Is Low Body Temperature Related to Hypertension?Cold settings cause an increase in blood pressure since the contraction of the blood vessels enhances resistance. According to some research studies, lower core body temperature may be related to the rising rate of blood pressure. If you feel cold intolerance with the simultaneous onset of high blood pressure, it would be worth your while to consult with your doctor to have proper assessment.How to Read Your Own Body TemperatureSometimes, a low temperature reading may be due to improper use of a thermometer. To ensure accuracy:Use a digital thermometer, which provides the most reliable results.Place the thermometer in contact with the skin or use oral or rectal methods for better accuracy.Hold the thermometer steady until it signals that the reading is complete.Taking multiple readings can also help confirm accuracy.When Should You See a Doctor?Not all temperature fluctuations are a cause for alarm. However, you should consult a doctor if your temperature remains below 97 degrees Fahrenheit and is accompanied by symptoms such as fatigue, shivering, or confusion.For temperatures below 95 degrees Fahrenheit, medical attention is necessary immediately. Symptoms of severe hypothermia or sepsis, such as slow breathing, disorientation, and a weak pulse, should be treated in an emergency.Disclaimer: This article is for informational purposes only and is not a substitute for professional medical advice. Always consult your healthcare provider for diagnosis and treatment of medical conditions.Body temperature norms. NIHThermoregulatory disorders and illness related to heat and cold stress. Autonomic Neuroscience. 2016Wernicke-Korsakoff syndrome. NIHQuantification of Human Thermal Risks During Ambient Temperature Steps Based on Fuzzy Comprehensive Evaluation. AATCC Journal of Research. 2024