Weed Chills: Biological Causes and Body Temperature Responses

Some cannabis users report experiencing chills or sudden feelings of cold after consumption, raising questions about the biological mechanisms behind this response. While not as widely discussed as effects like dry mouth or increased appetite, these temperature fluctuations suggest an interaction between cannabinoids and the body’s thermoregulatory system.

Understanding why these chills occur requires exploring how cannabis affects body temperature regulation and what factors contribute to individual differences in response.

Biology Of Chills

Chills, characterized by involuntary muscle contractions and a sensation of cold, are regulated by the hypothalamus, the brain’s thermoregulatory center. This region monitors temperature changes and triggers physiological responses to maintain homeostasis. When the body perceives a drop in temperature, the hypothalamus signals skeletal muscles to contract, generating heat through shivering. Vasoconstriction, the narrowing of blood vessels, reduces heat loss from the skin. While chills are commonly associated with fever or cold exposure, they can also result from neurochemical fluctuations that alter temperature perception.

Neurotransmitters like dopamine, serotonin, and norepinephrine influence thermoregulation. Dopamine, in particular, has been linked to temperature perception, with research in The Journal of Neuroscience showing that dopamine receptor activation in the hypothalamus can shift thermoregulatory set points, leading to cooling sensations. Similarly, serotonin plays a role in temperature control, with selective serotonin reuptake inhibitors (SSRIs) sometimes causing dysregulation as a side effect.

The autonomic nervous system (ANS) also plays a role in generating chills. The ANS, which regulates involuntary functions, consists of sympathetic and parasympathetic branches. When the sympathetic nervous system is activated, it can induce shivering and vasoconstriction as part of a broader arousal response. A study in Psychophysiology found that intense emotional reactions could cause measurable decreases in skin temperature, reinforcing the link between autonomic activity and chills.

Possible Mechanisms In Cannabis Use

Cannabis affects thermoregulation through the endocannabinoid system (ECS), a network of receptors and signaling molecules involved in numerous physiological processes. The ECS includes cannabinoid receptors type 1 (CB1) and type 2 (CB2), distributed throughout the central nervous system and peripheral tissues. CB1 receptors, concentrated in the hypothalamus, influence temperature regulation. Research in Nature Neuroscience indicates that CB1 activation can alter hypothalamic signaling, leading to transient reductions in core body temperature, a phenomenon known as cannabinoid-induced hypothermia.

THC, the primary psychoactive compound in cannabis, binds to CB1 receptors and disrupts normal thermoregulatory functions. A study in The Journal of Pharmacology and Experimental Therapeutics found that THC administration in rodents consistently reduced body temperature in a dose-dependent manner. This effect likely results from THC’s inhibition of excitatory neurotransmitters like glutamate, which plays a role in thermal homeostasis. By dampening excitatory signaling in the hypothalamus, THC shifts the body’s temperature set point, inducing cold sensations even in neutral ambient conditions.

Other cannabinoids, such as cannabidiol (CBD), may also influence temperature perception, though their effects are more variable. Unlike THC, CBD has a lower affinity for CB1 receptors and interacts with serotonin receptors involved in thermoregulation. Some studies suggest CBD may counteract THC-induced hypothermia. A 2019 review in Frontiers in Neuroscience highlighted findings where CBD administration mitigated temperature fluctuations in animal models. This suggests that cannabinoid composition influences whether a user experiences chills, with THC-rich strains being more likely to induce cooling sensations.

Thermoregulatory Responses With Cannabinoids

The body’s ability to regulate temperature depends on a balance between heat production and dissipation, controlled by the hypothalamus. THC disrupts this balance by altering neural pathways responsible for thermal homeostasis. When THC binds to CB1 receptors in the hypothalamus, it interferes with normal signaling, often resulting in a mild but measurable drop in temperature. While generally transient, the intensity of this effect varies based on dosage, metabolic rate, and individual neurochemical differences.

Peripheral thermoregulatory responses, including vasodilation and vasoconstriction, are also affected by cannabinoids. THC can induce vasodilation, increasing blood flow to the skin and creating a sensation of warmth. However, this can accelerate heat loss, making individuals feel colder in cooler environments. Some users may experience alternating sensations of warmth and chills after cannabis consumption. Additionally, cannabinoids influence sweat gland activity. A study in Clinical Autonomic Research found that cannabis use could reduce sweat production in certain individuals, further complicating temperature regulation.

Environmental conditions and behavior also shape thermoregulatory responses. THC’s depressant-like effects reduce physical activity, diminishing heat production from muscle contractions. This is particularly relevant in colder settings, where decreased metabolic heat generation makes cannabis’s cooling effects more pronounced. The sedative properties of some strains may also affect circulation and posture, increasing susceptibility to cold sensations. These factors highlight the interplay between physiological, behavioral, and environmental variables in determining how cannabinoids influence body temperature.

Correlation With Frequency

The frequency of cannabis use appears to influence temperature fluctuations, with both acute and long-term exposure shaping thermoregulatory responses. Occasional users often report more pronounced chills than frequent users, suggesting that tolerance develops over time. This adaptation is primarily due to receptor desensitization, where repeated CB1 activation leads to a diminished physiological response. As a result, regular users may experience less noticeable temperature changes.

Metabolic adaptations also play a role in reducing the intensity of chills with frequent use. THC is lipophilic, accumulating in fat stores and gradually releasing into the bloodstream. In chronic users, this slow-release mechanism results in more stable cannabinoid levels, preventing sudden thermoregulatory shifts. This could explain why new or infrequent users are more likely to experience abrupt changes in body temperature, as their systems are not yet conditioned to cannabinoids’ effects.

Other Contributing Factors

Beyond the direct effects of cannabinoids on thermoregulation, individual differences and external variables shape the likelihood and severity of chills. Genetic variations in the ECS influence how receptors respond to THC, making some individuals more prone to temperature fluctuations. Polymorphisms in the CNR1 gene, which encodes the CB1 receptor, affect cannabinoid sensitivity and thermoregulatory responses. Baseline neurotransmitter levels, particularly in dopamine and serotonin pathways, also play a role in how cannabis alters temperature perception. Individuals with lower dopamine activity may experience more pronounced cooling sensations due to THC’s impact on thermoregulatory signaling.

Environmental context and physiological states further contribute to these experiences. Consuming cannabis in colder settings amplifies chills, as THC-induced vasodilation facilitates heat loss. Dehydration, common due to cannabis’s mild diuretic effects, disrupts normal thermoregulation. Nutritional status also influences responses, as metabolic rate and blood sugar levels affect heat production. Low blood glucose, which can occur if cannabis is consumed on an empty stomach, reduces energy availability for thermogenesis, exacerbating cold sensations. These factors illustrate the complex interplay between biological and situational influences in shaping how individuals experience temperature changes after cannabis use.