Feeling alternately hot and cold can be a perplexing and uncomfortable experience, involving a fluctuating perception of body temperature. These shifts are often signals from the body reacting to internal processes or external conditions. Understanding common reasons for these sensations can provide clarity.
Body’s Natural Responses
The human body maintains a stable internal temperature through thermoregulation, managed by the brain’s hypothalamus. When disrupted, hot or cold sensations can arise as the body attempts to restore equilibrium.
During infection, the immune system releases pyrogens, signaling the hypothalamus to raise body temperature, initiating a fever. This brings chills as the body generates heat. Once the fever breaks, the body cools through sweating and blood vessel dilation, leading to warmth or hot flashes.
Chills occur without fever due to environmental or physical factors. Exposure to cold triggers shivering, a muscular contraction producing heat. Following intense physical exertion, the body cools, leading to a temporary cold sensation as heat dissipates.
Changes in blood vessel diameter, known as vasomotor responses, contribute to temperature shifts. Vessels near the skin constrict to conserve heat, reducing surface blood flow and creating a colder sensation. Conversely, these vessels dilate to release heat, increasing blood flow to the skin and generating a warm feeling. These adjustments cause alternating hot and cold sensations.
Hormonal and Metabolic Factors
Hormonal and metabolic imbalances can disrupt body temperature regulation, often leading to hot and cold sensations.
Hormonal shifts cause these sensations, especially during menopause or perimenopause. Fluctuating estrogen levels affect the hypothalamus, triggering hot flashes and night sweats. These heat sensations, often with sweating, can alternate with chills as the body attempts cooling.
Thyroid disorders impact metabolism and temperature perception. An overactive thyroid (hyperthyroidism) accelerates metabolism, causing warmth or heat intolerance. Conversely, an underactive thyroid (hypothyroidism) slows metabolism, often resulting in cold intolerance and chills.
Diabetes can impair thermoregulation due to its effects on the nervous and circulatory systems. Nerve damage (neuropathy) hinders the body’s ability to sense temperature changes or regulate sweating and blood flow. Blood sugar fluctuations affect heat dissipation or conservation.
Anemia, characterized by reduced healthy red blood cells, leads to cold sensations. Red blood cells transport oxygen and heat via hemoglobin. With fewer red blood cells, the body struggles to generate and distribute warmth, causing cold intolerance.
External and Lifestyle Influences
Various external and lifestyle factors can trigger fluctuating body temperature sensations.
Stress and anxiety activate the “fight or flight” response, releasing adrenaline that alters blood flow. As blood vessels constrict or dilate, individuals might feel warmth, flushing, or chills.
Certain medications can disrupt thermoregulation. Drugs affecting blood pressure, hormones, or metabolism interfere with stable temperature, causing increased sensitivity to heat or cold.
Diet and hydration influence temperature perception. Dehydration impairs temperature regulation, making individuals feel overheated or cold. Spicy foods, caffeine, or alcohol can affect circulation and metabolic rate, contributing to warmth or flushing.
Rapid environmental temperature changes challenge the body. Moving between warm and cold environments forces the thermoregulatory system to work, often resulting in hot flashes or chills.
When to Seek Medical Guidance
While occasional hot and cold sensations are harmless, some situations warrant medical evaluation. Consult a healthcare professional if these sensations become persistent, severe, or worsen, interfering with daily life.
Seek medical attention if temperature fluctuations are accompanied by concerning symptoms. These include unexplained weight loss, fatigue, pain, skin changes, or a fever that does not resolve. Such signs could indicate an underlying condition.
If these sensations cause discomfort or anxiety, seek professional advice. A medical professional can assess symptoms, conduct tests, and provide a diagnosis and treatment plan.