Cocaine is a powerful central nervous system (CNS) stimulant derived from the leaves of the coca plant. Its use is commonly associated with euphoria and increased energy, but it also produces intense physical effects. Many users report a noticeable sensation of coldness, leading to a misconception about the drug’s overall effect on body temperature. This feeling of cold is a peripheral symptom that often masks a much more serious internal process concerning the body’s thermal regulation.
How Cocaine Acts as a Stimulant
Cocaine exerts its stimulating effect by interfering with the brain’s chemical communication system. The drug rapidly crosses the blood-brain barrier and acts primarily by blocking the reuptake of specific neurotransmitters, which are chemical messengers used by nerve cells. This action particularly affects dopamine, norepinephrine, and serotonin.
By preventing their normal recycling, cocaine causes a sustained buildup of these neurotransmitters in the synaptic cleft, the space between neurons. The resulting surge in norepinephrine, a chemical involved in the body’s “fight or flight” response, accelerates systemic functions. This leads to an increase in heart rate, a rise in blood pressure, and an acceleration of the body’s metabolic rate.
The Physiological Cause of Feeling Cold
The sensation of coldness following cocaine use is a direct result of its impact on the circulatory system, specifically a process known as vasoconstriction. Cocaine’s stimulant properties cause the small muscles in the walls of the blood vessels to tighten, narrowing the peripheral blood vessels beneath the skin in the extremities.
Vasoconstriction limits blood flow to the skin surface in areas like the hands, feet, and nose. Since blood is the primary carrier of heat, reducing its flow to the periphery causes the skin temperature in these areas to drop. The user experiences this decreased skin temperature as the feeling of being cold, even though their core body temperature is actually rising.
The Greater Risk of Overheating
While the extremities may feel cold, cocaine simultaneously causes the body’s core temperature to rise, a condition known as hyperthermia. The drug’s stimulation of the central nervous system increases metabolic activity, which generates excess heat internally. This heat production is compounded because peripheral vasoconstriction, the mechanism that causes the cold sensation, prevents the body from cooling itself effectively.
The body normally dissipates heat by widening blood vessels near the skin (vasodilation) and producing sweat. Cocaine impairs both of these natural cooling mechanisms. By trapping the heat inside the body, the core temperature can climb to dangerous levels. Severe hyperthermia can lead to complications, including seizure, muscle breakdown (rhabdomyolysis), and organ failure.