Dozens of commonly prescribed and recreational drugs can make you feel cold, and they do it through several distinct routes: some reset your brain’s internal thermostat downward, some widen or narrow blood vessels in ways that dump heat or starve your extremities of warm blood, some blunt your body’s ability to shiver, and some rewire the nerve endings that sense temperature in the first place. Body temperature is a balance of the hypothalamic set point, neurotransmitter activity, heat generation, and heat dissipation, and drugs can disrupt any part of that chain.
How Drugs Tamper with Your Internal Thermostat
Your hypothalamus acts like a thermostat, constantly comparing incoming temperature signals against a target set point and triggering responses such as shivering, sweating, or redirecting blood flow. Drugs that make you feel cold generally interfere with one or more steps in that loop. Some push the set point itself lower, so the brain “decides” the body should be cooler than it actually needs to be. Others block the warming responses the brain tries to activate, like shivering or constricting blood vessels near the skin. Still others change how sensory nerves detect temperature, making ordinary cool air feel painfully cold. The distinction matters because the type of cold sensation you experience, and what you can do about it, depends on which step is being disrupted.
Certain drugs cause hypothermia specifically by depressing the thermoregulatory set point or by preventing the body from conserving heat.1PubMed. The effects of drugs on thermoregulation Neurotransmitters like dopamine, serotonin, and acetylcholine all play roles in the hypothalamus’s temperature-control circuitry, and drugs that block or flood those signaling pathways can throw the whole system off. For example, research in animals has shown that activating certain cholinergic receptors in the hypothalamus effectively lowers the thermostat’s set point, which could explain why drugs that mimic acetylcholine tend to produce hypothermia.2Brain Research. The effects of acetylcholine and nicotine on unit activity in the hypothalamic thermoregulatory centers of the rat
Opioids and the Shivering Response
Opioids are among the most studied drugs when it comes to thermoregulation, and their effects are more nuanced than simply “making you cold.” Both pure mu-receptor opioids and mixed mu/kappa-receptor opioids impair the body’s thermoregulatory control, but they do so in somewhat different ways. Pure mu-receptor agonists like alfentanil slightly raise the sweating threshold while markedly lowering the thresholds for vasoconstriction and shivering, meaning your body has to get considerably colder before it starts defending itself against heat loss.3PubMed. The effect of opioids on thermoregulatory responses in humans and the special antishivering action of meperidine In practical terms, you lose heat through your skin more freely because your blood vessels do not constrict as early as they normally would, and you do not start shivering until your core temperature has dropped further than it should.
Meperidine is an interesting case. It reduces the shivering threshold about twice as much as the vasoconstriction threshold, creating an unusually wide gap where your blood vessels have already begun constricting but your muscles still refuse to shiver.3PubMed. The effect of opioids on thermoregulatory responses in humans and the special antishivering action of meperidine Even once shivering finally kicks in, its intensity is diminished. This is actually why meperidine has historically been given to treat post-anesthetic shivering, but it also means that someone using opioids in a cold environment is at genuine risk of their core temperature dropping without the warning signs they would normally feel.
At low doses, opioids like morphine can paradoxically raise the thermostat’s set point in animals, producing a mild fever partly by reducing heat loss through the skin.4European Journal of Pharmacology. Morphine hyperthermia in the rat: An action of the central thermostats Higher doses tend to flip toward hypothermia. This dose-dependent reversal is one reason opioid users sometimes report contradictory temperature sensations: feeling flushed at one point and chilled at another.
Antipsychotics and Serotonin-Active Psychiatric Drugs
Antipsychotic medications are a well-documented cause of hypothermia, though it remains a relatively rare side effect. The mechanism ties back to dopamine receptors in the hypothalamus. Under normal conditions, D2 receptors help keep core body temperature stable, while D1 receptors play a modulating role. When an antipsychotic strongly blocks D1 receptors, core temperature can fall.5PubMed Central. Hypothermia due to Antipsychotic Medication: A Systematic Review Antipsychotics that strongly antagonize serotonin 5-HT2 receptors also appear to cause hypothermia more often.6PubMed Central. Approach to Low Body Temperature or Mild Hypothermia in the Geriatric Population: A Narrative Review The same family of drugs can cause the opposite extreme: massive D2 blockade is implicated in dangerously high body temperatures, as seen in malignant antipsychotic syndrome. So the relationship between antipsychotics and temperature is a matter of which receptors are most affected and to what degree.
Antidepressants, particularly selective serotonin reuptake inhibitors (SSRIs), can also contribute to feeling cold. Deaths linked to hypothermia have been associated with antidepressant use, though the exact mechanism remains unclear. Animal research suggests that fluoxetine may potentiate drops in body temperature.6PubMed Central. Approach to Low Body Temperature or Mild Hypothermia in the Geriatric Population: A Narrative Review Serotonin is deeply intertwined with temperature regulation: a subpopulation of serotonergic neurons in the brainstem appears to be thermosensitive, forming part of a pathway that links warmth perception to mood and physiology.7SAGE Journals (Journal of Psychopharmacology). That warm fuzzy feeling: brain serotonergic neurons and the regulation of emotion Altering serotonin levels pharmacologically can therefore have unpredictable downstream effects on how warm or cold you feel.
Beta-Blockers and Blood Pressure Medications
Cold hands and feet are one of the most common complaints from people taking beta-blockers, the class of drugs widely prescribed for high blood pressure, heart failure, and anxiety-related heart symptoms. Beta-blockers work by dampening the effects of adrenaline, which normally keeps your heart rate up and blood vessels responsive. As a side effect, many beta-blockers promote vasoconstriction in the peripheral blood vessels, particularly in the fingers and toes, restricting warm blood flow to the extremities. A systematic review found that beta-blockers have variable tendencies to enhance peripheral vasoconstriction, and this effect does not simply track with whether a drug is “selective” for the heart’s beta-1 receptors or not.8PubMed Central. Peripheral vasoconstriction induced by β-adrenoceptor blockers: a systematic review and a network meta-analysis In other words, switching to a so-called cardioselective beta-blocker will not necessarily fix cold extremities. Some people find the cold-hands effect tolerable; others, especially those with pre-existing circulation issues, find it miserable.
Vasodilators present a different problem. Drugs like nifedipine, a calcium channel blocker used for high blood pressure and angina, widen blood vessels. You might expect that to make you feel warmer, since more blood reaches the skin. But opening up blood vessels also accelerates heat loss from the body’s core. In a surgical setting, patients given nifedipine before anesthesia experienced a core temperature drop of about 2°C in the first hour, a clinically significant amount.9PubMed. Nifedipine and intraoperative core body temperature in humans Outside of surgery, the effect is less dramatic but still noticeable. You might feel a brief flush of warmth in the skin from increased blood flow, followed by a general sense of being chilled as your core gives up heat faster than your metabolism can replace it.
Chemotherapy and Rewired Cold Sensors
The cold sensitivity caused by oxaliplatin, a chemotherapy drug commonly used for colorectal cancer, is unlike anything caused by the drugs discussed so far. This is not a thermostat problem or a blood flow problem; it is a nerve-wiring problem. Oxaliplatin changes how your sensory nerve endings detect temperature, making normal cool sensations feel intensely painful. Cold hypersensitivity develops in nearly all patients receiving oxaliplatin, making it the hallmark side effect of this drug.10PubMed Central. Oxaliplatin-induced cold hypersensitivity is due to remodelling of ion channel expression in nociceptors
The mechanism involves remodeling of the ion channels in pain-sensing nerve fibers. Oxaliplatin drastically lowers the expression of certain potassium channels (TREK1 and TRAAK) that normally act as brakes on nerve firing, while increasing the expression of channels that make the nerve more excitable. It also upregulates the cold-sensing receptor TRPM8, so the nerves that detect coolness become far more sensitive than they should be.10PubMed Central. Oxaliplatin-induced cold hypersensitivity is due to remodelling of ion channel expression in nociceptors A separate pathway involves the cold receptor TRPA1, which oxaliplatin sensitizes by inhibiting an enzyme that normally keeps it in check.11Frontiers in Pain Research. Pathological Mechanisms and Preventive Strategies of Oxaliplatin-Induced Peripheral Neuropathy
For patients, this translates into acute symptoms during or shortly after infusion: touching a cold glass, breathing cool air, or reaching into a refrigerator can cause sharp pain or tingling in the hands, feet, and throat. The effect can be so severe that patients learn to avoid all cold contact during treatment weeks. There is some evidence that calcium channel blockers may reduce the incidence of this acute neuropathy. A review of medical records of patients on oxaliplatin-based regimens found that those also taking calcium channel blockers had a significantly lower incidence of acute peripheral neuropathy.11Frontiers in Pain Research. Pathological Mechanisms and Preventive Strategies of Oxaliplatin-Induced Peripheral Neuropathy Research into targeted treatments continues, with some promising leads involving specific T-type calcium channel interactions.12PubMed. Contribution of T-type calcium channel isoforms to cold and mechanical sensitivity in naïve and oxaliplatin-treated mice of both sexes
Sedatives, Alcohol, and Cannabinoids
Benzodiazepines and related sedatives lower body temperature in a dose-dependent fashion. Diazepam, lorazepam, and the sleep aid zolpidem have all been shown to produce measurable decreases in body temperature alongside reductions in muscle activity and movement.13PubMed. The acute effects of zolpidem compared to diazepam and lorazepam using radiotelemetry The reduced muscle activity is part of the story: muscles generate heat, and sedatives quiet them down. The drugs also act on the central nervous system in ways that dampen the brain’s drive to maintain normal temperature.
Alcohol is the classic case of a drug that makes you feel warm while actually making you colder. Drinking dilates blood vessels near the skin, creating a pleasant flushing sensation, but this accelerates heat loss from the core. Alcohol delays the onset of shivering and shortens its duration, removing one of the body’s most important defenses against cold. It also promotes cold-related urine output, reducing blood volume and further compromising the body’s ability to maintain temperature during prolonged cold exposure.14PubMed Central. Alcohol and cold The danger is especially real for anyone drinking outdoors in winter: the subjective warmth masks a body that is losing heat faster than it otherwise would.
Cannabis follows a dose-dependent pattern. At lower doses, THC can slightly raise body temperature. At higher doses, it drives temperature down, decreasing heat production. Research in rats found that true hypothermia only appeared at the highest doses, with temperature drops in the brain outpacing those in muscle tissue, suggesting the cooling effect originates from metabolic suppression in the brain rather than from changes at the body’s surface.15PubMed Central. Behavioral and temperature effects of delta 9-tetrahydrocannabinol in human-relevant doses in rats This bidirectional effect, where low doses warm and high doses cool, has been confirmed across multiple studies.16PubMed. The role of endocannabinoids in the hypothalamic regulation of visceral function The hypothermia from THC can be reversed by blocking the CB1 cannabinoid receptor, confirming that at least part of the effect runs through the endocannabinoid system, though researchers have noted that the cooling pattern also resembles what general anesthetics produce, raising questions about how specific the mechanism truly is.17Life Sciences. Δ9-tetrahydrocannabinol (Δ9-THC) prevents cerebral infarction via hypothalamic-independent hypothermia
Nicotine and the Cold-Hands Paradox
Nicotine occupies an odd position in this list. It is a stimulant that typically raises heart rate and blood pressure, so you might expect it to warm you up. Instead, smoking reliably drops the surface temperature of the fingers and toes, sometimes dramatically. Cigarette smoking produces vasoconstriction in the extremities, reducing cutaneous blood flow and lowering skin temperatures that can be measured at the fingertips and toe tips.18JAMA. THE EFFECT OF SMOKING CIGARETS: AND OF INTRAVENOUS ADMINISTRATION OF NICOTINE ON THE ELECTROCARDIOGRAM, BASAL METABOLIC RATE, CUTANEOUS TEMPERATURE, BLOOD PRESSURE AND PULSE RATE OF NORMAL PERSONS Early research demonstrated that in many smokers, blood flow in the extremities could slow markedly and even stop temporarily after smoking.19JAMA. THE EFFECTS OF TOBACCO ON THE PERIPHERAL VASCULAR SYSTEM: FURTHER STUDIES
The mechanism is straightforward: nicotine stimulates the sympathetic nervous system, which constricts the small blood vessels in the hands and feet as part of a general “fight or flight” response. Your core stays warm, but your extremities pay the price. For most smokers, this is a minor annoyance. For people with pre-existing vascular disease, it can be a real problem, worsening conditions like Raynaud’s phenomenon where blood flow to the fingers already shuts down excessively in the cold.
Drugs That Interfere with Thyroid Function
Feeling persistently cold is one of the hallmark symptoms of hypothyroidism, because thyroid hormones are central to the body’s metabolic rate and heat production. Several medications can push thyroid function lower by suppressing thyroid-stimulating hormone (TSH) at the level of the pituitary gland or hypothalamus. Glucocorticoids, dopamine agonists, and somatostatin analogues all suppress TSH to varying degrees. A newer class of drugs called rexinoids causes clinically significant central hypothyroidism in most patients who take them.20PubMed Central. Drugs that suppress TSH or cause central hypothyroidism Dopamine agonists may also worsen hypothyroidism in people who already have suppressed thyroid function from illness.
The cold intolerance from drug-induced hypothyroidism tends to be more diffuse and chronic than the acute chills caused by, say, an opioid or a beta-blocker. It is a whole-body slowdown: you feel cold all over, your energy drops, and your tolerance for cool environments shrinks. If you have recently started one of these medications and find yourself reaching for extra layers more often than usual, it is worth having your thyroid levels checked.
Why Older Adults Are Especially at Risk
Aging itself blunts thermoregulation. Older adults have diminished shivering responses, less insulating body fat in some cases, and reduced ability to sense temperature changes. Layered on top of that is the reality that older adults take more medications, often several at once. Polypharmacy is one of the most common causes of low body temperature in geriatric patients, because the thermoregulatory side effects of individual drugs can stack.6PubMed Central. Approach to Low Body Temperature or Mild Hypothermia in the Geriatric Population: A Narrative Review An older person taking an antipsychotic, an SSRI, and an opioid for pain might experience a combined cooling effect that none of those drugs would produce alone.
Elderly populations are prone to both dangerously high and dangerously low body temperatures because of age-related physiologic changes, chronic disease, and the cumulative effects of multiple medications.21PubMed. Hyperthermia and hypothermia in the elderly The clinical implication is that mild hypothermia in an older adult should prompt a medication review, not just a blanket. Even small drops in core temperature can impair cognition and increase fall risk in someone already on the edge of stable health.
When Feeling Cold Means Something Is Wrong
Most drug-induced chills are uncomfortable but not dangerous. Cold fingers from a beta-blocker, a chill after a glass of wine on a cool night, goosebumps during a THC experience: these are the body responding predictably to a chemical nudge, and they resolve as the drug wears off or as you warm up. The situations that warrant medical attention are different. A sustained drop in core temperature below about 35°C (95°F) is hypothermia, and it can be life-threatening. People who are sedated, intoxicated, or on high doses of antipsychotics may not recognize how cold they are getting, because the same drugs that lower their temperature also impair their awareness of it.
Oxaliplatin-induced cold sensitivity is not dangerous in the way hypothermia is, but it is clinically significant because of how much it affects daily life during treatment. Oncologists routinely counsel patients to avoid cold drinks, wear gloves before reaching into the freezer, and cover exposed skin in cool weather. If cold sensitivity worsens across treatment cycles or begins affecting motor function in the hands, the chemotherapy dose may need adjustment.
For anyone taking a medication and noticing new or worsening cold sensitivity, the first step is recognizing that the drug could be the cause. Many people assume they are “just getting older” or “not dressing warmly enough” when the real culprit is sitting in their medicine cabinet. Bringing it up with a prescriber can sometimes lead to a dosage change, a switch to a different drug in the same class, or at least an explanation that makes the symptom less alarming.