Debunking the Myth: Overheating, Not Chill, Induces Sleepiness

Contrary to popular belief, a cool room does not cause sleepiness. Physiological studies show that it is the overheating of the body—especially when combined with dehydration—that provokes feelings of fatigue and drowsiness. When the temperature rises, our body starts to fight to maintain its thermal balance, which can lead to a decrease in energy levels.

On the contrary, exposure to cold activates defensive reflex mechanisms: involuntary muscle contractions, which cause shivering, are the skin's natural response to cold, aimed at preserving the optimal body temperature. This mechanism signals not tiredness but rather vitality, enabling us to effectively cope with external climatic changes.

Thus, regulating the temperature in a room is key to sustaining health and alertness, and a proper understanding of the underlying physiological processes helps us care better for our body.

How does low room temperature affect the onset of sleepiness? Based on the presented materials, there is no direct evidence that low indoor temperatures lead to sleepiness. On the contrary, one of the sources indicates that sleepiness is “a typical manifestation of high body temperature and a critical deficiency of fluids in the body” (source: 1350_6746.txt). This suggests that it is overheating and its related processes that may contribute to the onset of drowsiness.

Furthermore, another source describes in detail how exposure to cold triggers a series of defensive reflex mechanisms, such as shivering, which occurs as a result of skin irritation by cold and causes involuntary muscle contractions (source: 1890_9445.txt). Such reactions are aimed at maintaining the body temperature rather than inducing a state of sleepiness.

Thus, according to the cited materials, low room temperature is not considered a factor causing sleepiness; on the contrary, drowsiness is associated with the state of an overheated body, while cold generally activates physiological reflexes to maintain the optimal temperature.

Supporting citation(s):
"Child’s Sleep as a Health Indicator": "Any significant deviations from the normal sleep schedule—sudden awakening at unusual times and especially (!) the desire to sleep at unusual times—are very concerning signs [...] It should be remembered that sleepiness is typically a manifestation of high body temperature and a critical deficiency of fluids in the body." (source: 1350_6746.txt)
"Shivering as a Response to Cold": "Instinct leads us there, and one does not need to be a physiologist to know that walking and muscle work can help maintain a steady temperature even in very severe cold. But besides instinct, there are also special reflexes: shivering, reflex movement [...] Clearly, it occurs due to the skin being irritated by the sensation of cold." (source: 1890_9445.txt)