The sensation of rapidly shifting between feeling hot and cold can be confusing. This reflects the body’s system for maintaining a stable internal temperature, which various factors can challenge. Understanding these shifts involves looking into the processes that govern thermal balance.
Understanding Your Body’s Thermoregulation
The human body maintains a core temperature of approximately 37 degrees Celsius (98.6 degrees Fahrenheit) for optimal functioning. This regulation is primarily managed by the hypothalamus, a region in the brain acting as the body’s thermostat. The hypothalamus constantly monitors blood temperature and receives signals from temperature sensors throughout the body.
When the body’s temperature deviates from its set point, the hypothalamus initiates mechanisms to conserve or dissipate heat. To cool down, it triggers vasodilation, widening blood vessels near the skin surface to radiate heat away. Sweating also occurs, and as moisture evaporates, it carries heat from the body. Conversely, to warm up, the hypothalamus causes vasoconstriction, narrowing blood vessels to reduce heat loss. Shivering, an involuntary muscle contraction, generates heat through increased metabolic activity.
Common Causes of Hot and Cold Sensations
Various factors can temporarily disrupt the body’s thermoregulatory balance, leading to alternating sensations of hot and cold. These disruptions often stem from the body’s attempts to adjust to internal or external changes.
Illness and Infection
When the body encounters pathogens, the immune system can trigger a fever. During a fever, the hypothalamus resets the body’s temperature set point to a higher level. As the body works to reach this new temperature, individuals often experience chills and shivering, feeling cold even as their internal temperature rises. Once the fever breaks or the body reaches the elevated set point, it then works to cool down, leading to sensations of heat and sweating.
Hormonal Fluctuations
Shifts in hormone levels can impact the hypothalamus and its ability to regulate temperature, leading to hot flashes and night sweats. This is common during menopause, perimenopause, menstruation, or pregnancy. Fluctuating estrogen levels can make the hypothalamus hypersensitive to small changes in core body temperature, triggering an exaggerated cooling response. This manifests as a sudden feeling of intense heat, often with sweating, followed by chills as the body overcools.
Stress, Anxiety, and Panic Attacks
The body’s “fight or flight” response, activated by stress, anxiety, or panic attacks, can lead to temperature fluctuations. Under stress, the adrenal glands release adrenaline, altering blood flow and metabolism. This can cause blood vessels to constrict in some areas and dilate in others, leading to sensations of heat or flushing. As the body attempts to return to a calm state, it might overcompensate, resulting in chills or cold flashes.
Environmental Factors
Rapid changes in external temperature can overwhelm the body’s thermoregulatory system. Moving from a warm environment into a cold one, or vice-versa, requires the body to quickly adjust its heat conservation or dissipation mechanisms. For instance, entering a cold room from a hot outdoor setting might initially cause shivering and a feeling of cold. As the body adapts, it might then feel warm.
Medication Side Effects
Certain medications can interfere with the body’s thermoregulatory processes, leading to sensations of hot and cold as a side effect. Some drugs affect the hypothalamus directly, while others impact sweating, blood flow, or metabolic rate. For example, some medications can reduce the ability to sweat, making it harder for the body to cool down and leading to overheating sensations. Conversely, other medications might cause changes in blood vessel dilation or constriction.
When to Consult a Healthcare Professional
While alternating hot and cold sensations can be a normal or temporary symptom, medical evaluation is advisable in some instances. Seeking professional advice is important if these sensations become persistent, severe, or are accompanied by other concerning symptoms. A healthcare provider can help determine the underlying cause and recommend management.
It is important to consult a doctor if hot and cold sensations are accompanied by a high fever, especially if it reaches 39.4 degrees Celsius (103 degrees Fahrenheit) or higher in adults. Other symptoms warranting attention include severe pain, confusion, shortness of breath, or unexplained weight loss. Sensations that occur suddenly without an obvious cause, significantly disrupt daily life, or do not improve with self-care warrant prompt medical attention.