A hot toddy feels warm going down. Your body, though, may be losing heat, not gaining it. Alcohol changes how warm you feel more reliably than it changes how warm you are.
Why a drink feels warm
Your brain keeps your core temperature steady by adjusting blood flow to your skin. When you are cold, vessels near the skin narrow so less heat escapes. Alcohol widens those vessels. More warm blood reaches the surface, and your skin and face feel hot. In a recent Guardian explainer, toxicologist Winston Morgan of the University of East London put it this way: your body is moving blood around, not making you warmer.
What the research says about core temperature
This is where the common explanation gets less tidy. A 1994 review in the Journal of Wilderness Medicine pulled together the studies on alcohol and cold exposure and found that the older results conflicted. The authors traced much of that to differences in dose, how cold it was, what people had eaten and their body composition.[1]
Once those factors were sorted out, the review concluded that alcohol tends to lower core body temperature during cold exposure, and that the drop grows with blood alcohol level. The review found that how cold it was and a person’s body composition changed the size of the effect, and that low blood sugar made it much worse.[1]
The review also challenged the popular story. Its authors proposed that the main reason alcohol worsens the fall in core temperature is weaker shivering, tied to alcohol-induced low blood sugar, rather than extra heat escaping through widened skin vessels.[1] So the “blood moves to the skin” explanation is real, but it may not be the whole mechanism.
One experiment shows how much the details matter. In a 1977 study, volunteers who had been drinking were immersed in 13 degree C water for 20 minutes. Their blood alcohol averaged about 90 mg per 100 ml. That is a measurement from the experiment, not a safe or legal limit. Rectal, ear and skin temperatures did not differ significantly from their no-alcohol control sessions.[2] Twenty minutes is short, and the study did not test longer exposures, so it does not clear alcohol of risk outdoors.
What to do with this
- If you are cold, warm the room, add a layer or hold something warm. A warm non-alcoholic drink works for the feeling without the downside.
- Do not take off layers because a drink made you feel hot. That flush is a skin sensation, not a sign your core is warm.
- The research links low blood sugar to a bigger temperature drop, but it does not show that eating first or keeping your coat on makes drinking in the cold safe. If it is cold enough to matter, the lower-risk choice is to skip alcohol until you are indoors.
- Be careful when alcohol and cold overlap and you cannot easily get indoors, such as a long walk home, an outdoor event or a stalled car.
If you take medication, especially for diabetes, blood pressure, sleep or mood, or you have a heart or metabolic condition, ask your clinician or pharmacist how alcohol interacts with it before you drink, and how cold exposure might change that.
Shivering, slurred speech, confusion or clumsiness in the cold can be signs of hypothermia. Treat that as an emergency and call your local emergency number rather than waiting it out.
The limits
The evidence here is a 1994 review and one small lab experiment, so it is dated and limited. Real life adds wind, wet clothes, food, fatigue and how much you drank. This evidence does not measure risk from drinking in a warm room, so it neither supports nor rules out a problem there. How much alcohol is right for you, if any, is a question for your clinician. The takeaway is that alcohol is a poor tool for staying warm, and a risky one when it is cold enough to matter.
References
- Freund BJ, O’Brien C, Young AJ. Alcohol ingestion and temperature regulation during cold exposure. Journal of Wilderness Medicine. 1994. https://doi.org/10.1580/0953-9859-5.1.88 Finding used: narrative review; alcohol acts as a poikilothermic agent, lowering core temperature during cold exposure in proportion to blood alcohol concentration; cold severity and body composition modify the effect (direction not specified in the abstract); hypoglycemia greatly exacerbates the drop; impaired shivering thermogenesis from alcohol-induced hypoglycemia, rather than vasodilation, appears to be the primary mechanism. ↑︎ a b c
- Martin S, Diewold RJ, Cooper KE. Alcohol, respiration, skin and body temperature during cold water immersion. Journal of Applied Physiology. 1977. https://doi.org/10.1152/jappl.1977.43.2.211 Finding used: 20-minute immersion at 13 degrees C after alcohol (mean blood alcohol 90 mg/100 ml); no significant difference in rectal, aural or mean skin temperatures versus control immersions. ↑︎
Kurt Greiner
Kurt is a digital strategist and IT professional blending emerging technology with practical application, exploring how individuals can leverage modern tools to navigate the second half of life with purpose.
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