Medications can interfere with the body’s natural processes for maintaining a stable internal temperature, a system known as thermoregulation. This interference can result in a distorted perception of temperature or an actual drop in core body warmth, known as drug-induced cold sensation or hypothermia. Many pharmaceutical agents, ranging from heart medications to those affecting the nervous system, can inadvertently alter the delicate balance between heat production and heat loss. Understanding how these drugs interact with the body’s thermal controls explains why some people experience an unexpected feeling of coldness.
The Physiology of Drug Induced Cold Sensation
The body’s temperature is precisely controlled by the hypothalamus, a small region in the brain that acts as the central thermostat, setting the body’s desired temperature, or “set point.” Drugs can directly affect this set point, essentially tricking the hypothalamus into believing the body is too warm. This triggers cooling mechanisms, even if the actual core temperature is normal, causing a person to feel cold without a significant drop in body temperature.
A primary mechanism for regulating warmth is peripheral circulation, which controls blood flow near the skin’s surface. When the body needs to conserve heat, it triggers vasoconstriction, narrowing blood vessels in the extremities. Conversely, some medications cause vasodilation, widening the blood vessels and shunting warm blood closer to the skin. This accelerates heat loss to the environment, which can lead to a drop in core temperature and a distinct sensation of cold, particularly in the hands and feet.
Another way drugs affect warmth is by altering the body’s metabolic rate, the speed at which the body converts stored energy into heat. Heat generation (thermogenesis) is a natural byproduct of cellular activity, and a reduction in this activity lowers the total heat produced. Certain medications can suppress the metabolic rate, making it difficult for the body to generate sufficient heat to maintain its temperature. When these mechanisms are inhibited, the body’s defenses against cold are weakened, contributing to a cold feeling or hypothermia.
Types of Medications That Impact Body Temperature
Several classes of medications interfere with thermoregulation, often by affecting the cardiovascular or central nervous systems. Beta-blockers, commonly prescribed to treat high blood pressure and heart conditions, can induce cold sensations by reducing heart rate and decreasing blood flow to the extremities. This reduction in peripheral circulation is a direct result of the drug’s action and can leave hands and feet feeling persistently cold.
Certain psychotropic medications, including some antipsychotics and antidepressants, can disrupt the body’s temperature control. Antipsychotic drugs influence the hypothalamic set point by interacting with dopamine and serotonin receptors in the brain. This effect can impair the body’s ability to initiate warming responses like shivering or vasoconstriction, making the user vulnerable to a drop in temperature.
Medications that affect the thyroid gland, such as those used to treat an overactive thyroid (hyperthyroidism), can lead to cold intolerance. By lowering thyroid hormone levels, these drugs reduce the overall metabolic rate of the body. Since the metabolic rate is a primary source of internal heat generation, its reduction naturally leads to a decreased ability to stay warm.
Other drug categories, like certain general anesthetic agents and sedative-hypnotics, can cause a cold sensation by broadly depressing the central nervous system. This central depression impairs the body’s ability to sense cold and initiate protective responses, leading to increased heat loss. Even some chemotherapy agents are associated with cold sensitivity, often due to an unrelated effect on peripheral nerves (neuropathy), which changes how cold is perceived.
Managing the Feeling and Knowing When to Seek Care
If you feel a mild, persistent cold sensation after starting a new medication, several practical steps can manage the discomfort. Wearing multiple layers of clothing (layering) allows you to adjust insulation as needed throughout the day. Using warm accessories like gloves and thick socks can help counteract the peripheral cooling often experienced in the hands and feet.
It is helpful to maintain a slightly warmer environment at home or work to reduce external cold stress. Drinking warm beverages can provide a temporary internal warmth boost and help mitigate the sensation of coldness. Discussing the side effect with the prescribing doctor is important, as they may suggest a dosage adjustment or a switch to an alternative medication with less impact on thermoregulation.
While a mild cold feeling can be an expected side effect, a true drop in core body temperature (hypothermia) is a serious medical concern. Contact your doctor immediately if the cold feeling is accompanied by confusion, severe, non-stop shivering, or slurred speech. Emergency medical attention is necessary if you experience signs of severe hypothermia, such as lack of coordination, drowsiness, or a body temperature below 95°F (35°C). These signs indicate that the body’s temperature controls are dangerously compromised, requiring medical intervention.