Feeling hot and cold at night is a common experience, stemming from the body’s effort to maintain a stable core temperature, a process called thermoregulation. During sleep, thermoregulatory mechanisms adjust with sleep cycles and circadian rhythm. When this balance of heat production and dissipation is disrupted, individuals may alternate between feeling overheated and chilly.
Everyday Contributors
Common factors in daily routines and sleep environment influence nighttime temperature fluctuations. Bedroom temperature plays a substantial role; rooms too warm or cold disrupt the body’s natural cooling process essential for sleep. An ideal sleeping temperature range is 60 to 67 degrees Fahrenheit (15.6 to 19.4 degrees Celsius).
Bedding and sleepwear choices directly impact how the body manages heat. Non-breathable materials trap heat, leading to overheating and sweating. If sleepwear becomes damp from sweat, it can cause chills as the body attempts to cool. Opting for loose-fitting, breathable fabrics like cotton helps skin regulate temperature effectively.
Intense physical exercise before bedtime can elevate core body temperature for hours. While regular exercise benefits sleep, a strenuous workout too close to sleep makes it difficult for the body to cool sufficiently, potentially leading to overheating. As the body cools, a subsequent drop might cause chills.
Dietary choices and certain beverages before sleep contribute to temperature swings. Heavy meals or spicy foods increase metabolic activity, generating heat during digestion. Stimulants like caffeine raise body temperature and alertness, interfering with natural cool-down. Alcohol can also induce night sweats due to its effects on blood vessels and metabolism.
Hormonal and Physiological Influences
Hormonal fluctuations and natural physiological processes impact nighttime temperature regulation. Hormonal changes during perimenopause and menopause frequently cause hot flashes and night sweats. Declining estrogen levels disrupt the hypothalamus, the brain’s temperature control center, leading to sudden heat sensations. Decreased progesterone levels also contribute to feelings of warmth at night.
Other hormonal shifts can affect temperature. Premenstrual syndrome (PMS) involves hormonal fluctuations that lead to night sweats in some individuals. Stress and anxiety provoke physiological responses, activating the “fight-or-flight” system, which increases heart rate and blood flow, altering body temperature. This heightened state can manifest as warmth or sweating at night.
The circadian rhythm, the body’s internal clock, orchestrates a natural daily cycle of temperature changes supporting sleep. Core body temperature drops about two hours before sleep onset, reaching its lowest point in early morning. This decline helps initiate sleep and continues through non-rapid eye movement (NREM) stages. During rapid eye movement (REM) sleep, the body’s temperature regulation is limited, making individuals susceptible to external changes.
Potential Medical Explanations
Underlying medical conditions can lead to hot and cold sensations at night. Infections, bacterial or viral, commonly cause fevers as the body fights pathogens, often with sweating and chills.
Disruptions in thyroid function affect body temperature regulation. An overactive thyroid (hyperthyroidism) accelerates metabolism and increases heat production, causing excessive warmth at night. An underactive thyroid might cause coldness.
Certain medications list temperature changes, including night sweats, as a side effect. These include antidepressants, hormone therapies, and some diabetes medications. Consulting a healthcare provider can determine if a prescribed drug contributes to nighttime temperature issues.
Sleep disorders, such as obstructive sleep apnea, can interfere with thermoregulation. Sleep apnea involves repeated breathing interruptions during sleep, stressing the body and triggering sweating. Less common conditions, including autoimmune disorders or chronic stress, may also manifest with night sweats or chills.
Seeking Professional Guidance
If nighttime hot and cold sensations are persistent, worsen, or are accompanied by other concerning symptoms, consult a healthcare professional. Warning signs for medical attention include unexplained weight loss, persistent fatigue, unusual pain, or a prolonged fever. These symptoms could indicate an underlying medical condition requiring diagnosis and management.
If temperature fluctuations disrupt sleep quality or interfere with daily life, a doctor can help identify the root cause. A healthcare provider can conduct a thorough evaluation, reviewing medical history, performing a physical examination, and ordering diagnostic tests.