Does drinking alcohol really keep you warm?

Sorry Dr. Juan, but...

This column is starting to sound like Steve Wright's "factoids", but even more confused. You're in danger descending to Wikipedia levels of accuracy. I don't suppose there's any chance that you could actually get someone with qualifications in a genuine science to answer the science-related questions, is there? If you're stuck, I'll do it myself...

"Does drinking alcohol really keep you warm?

No!"

Well, this much is correct.

"Alcohol only gives a false sense of warmth,"

Under normal circumstances, when the body's core temperature drops by more than a degree or so, the blood vessels near the surface of the skin constrict, keeping the blood closer to vital organs and thus retaining heat. Alcohol, being - as mentioned - a vasodilator, prevents this mechanism from functioning effectively.

So, it's a real sense of warmth; your skin genuinely does get warmer and the warmth you are feeling is your core body heat being radiated from your skin. This is not a good thing if you're buried in the snow or going for a swim, as you will rapidly lose heat to your surroundings.

"In fact, while you get the feeling of warmth from alcohol, it is really unsuitable because it allows the cold to enter the body."

Oh, come ON! Cold doesn't "enter" the body, heat leaves it.

"Does drinking alcohol thin the blood?

No! Alcohol is a vasodilator."

Well, this is true as far as it goes. However, in the context of drinking alcohol when cold, there's another factor to mention. Most deaths involving cold in milder climates such as the UK's aren't from hypothermia, they're from the secondary effect of one's blood thickening. When you're cold for a protracted period, the reduced circulatory path (due to vasoconstriction in the extremities) means that internal organs get more heavily flooded with blood.

In order to reduce the load, the body excretes salt and water. This makes the blood thicker and more likely to clot, leading in an increased incident of heart attacks and strokes in vulnerable persons.

So, although alcohol doesn't thin the blood, it could prevent it thickening during a prolonged period of exposure to cold because it will prevent the usual restriction of circulation.

That's still not to say that consuming alcohol to keep warm is a good idea though...

"Why does drinking alcohol make you feel thirsty?

Alcohol ingestion forces the body to metabolise it in order to remain chemically balanced for proper body functioning.

Well, yes, like almost everything else you might ingest. "Chemically balanced for proper body functioning" sounds like a line from a pseudo-scientific commercial for the latest overpriced bottled water...

"In doing so, the body actually draws water from body tissues. This can cause a thirsty feeling."

This is an absolute load of cobblers. There is more than enough water content - by several orders of magnitude - in any alcoholic beverage to replace the water required for the metabolism of alcohol.

Nor is the other popular explanation - that alcohol is a diuretic - actually the real one. Although alcohol is a mild diuretic, it doesn't usually cause water loss in that manner beyond what is contained in the drink in the first place.

The actual reason that alcohol makes you feel thirsty is very simple: alcohol is an astringent. It does indeed abstract water from body tissues, but this has nothing to do with alcohol metabolism. It dries out your mouth and throat, causing you to feel "dehydrated", even though the chances are that you're no such thing! That's why you feel thirsty.

What on earth are they teaching PhD's in school these days, eh?