How does alcohol affect your body temperature?

In the UK, a great number of us enjoy alcohol on a regular basis. It's safe to assume that this isn't about to change, especially with the festive season and associated work parties and social get-togethers not far away. As long as we're sensible and aware of our units, our chances of developing health issues are low.

How many units of alcohol should we be drinking per week?

The Chief Medical Office recommends a limit of 14 units per week. However, according to the Office for National Statistics, 24% of adults in England and Scotland regularly drink over this amount each week. . They also report that 27% of drinkers in Great Britain binge drink on their heaviest drinking days.

What does alcohol do to your body?

Binge drinking and drinking over the recommended weekly units is when alcohol consumption can become dangerous. Binge drinking - consuming an excessive amount of alcohol over a short period - can lead to alcohol poisoning. Dangers of alcohol poisoning include:

• Heart attacks

• Severe dehydration

• Hypothermia

• Seizures

• Comas

• Brain damage

• Death

A long-term habit of excessive alcohol drinking could also result in serious health complications. These include:

• High blood pressure

• Liver disease

• Heart disease

• Diabetes

• Pancreatitis

• Cancer

These are the more extreme consequences of alcohol abuse. But even when consumed in moderation, alcohol temporarily alters our normal bodily functions. One such physiological change that occurs is to our body temperature. We may all recognise the symptoms, but what is actually going on and when can this become dangerous?

Why do I feel hot after drinking alcohol?

Your body temperature control, known as thermoregulation, is impacted when you consume alcohol. The alcohol causes unusual thermoregulation activity as it influences the mechanisms your body uses to either warm you up or cool you down.

As you drink alcohol your liver has the job of digesting it. Your liver can only digest so much alcohol at a time and the more you drink the longer it takes for the liver to perform this task. During this time, your liver gives off heat as it works and blood alcohol levels rise.

Over this period the alcohol in your system acts as a 'vasodilator'. This means that the alcohol widens and relaxes your blood vessels.

As people who flush red when they drink know, alcohol increases blood flow to the skin (called 'vasodilation'). "This increases skin temperature and makes you feel warm,” says Professor of human and applied physiology Michael Tipton.

Alcohol sweats

The warm and toasty feeling after drinking alcohol can be accompanied with sweating. This is another mechanism of thermoregulation that under regular circumstances is used by the body to lower its temperature through evaporation.

Some people are more susceptible to flushed, red cheeks than others. For example, this trait is more common in those with East Asian descent, due to a genetically determined deficiency of an enzyme which helps the liver break down alcohol.

According to the National Institute on Alcohol Abuse and Alcoholism, it's thought that with reduced quantities of this enzyme, certain by-products build up in the body which cause the flushing. The marked vasodilation in people with this genetic trait increases the volume in the blood vessels and reduces blood pressure - making them prone to low blood pressure and dizziness.

Hangover symptoms

You may have experienced hot flushes as a symptom of an alcohol hangover. This happens when your blood alcohol concentration levels return to normal. Usually, when you haven't consumed alcohol, these hot flushes are your body's signal to cool down. As a result, during a hangover this can cause abnormal changes to your thermoregulatory mechanisms.

What is really happening to your body temperature when you drink?

All these changes triggered by alcohol create the illusion of warmth. In fact, these symptoms are causing your body temperature to drop. Tipton explains:

"By flushing and sweating you are delivering more heat to the skin and thereby increasing heat loss from the 'core' of the body to the environment."

Do hot flushes raise your body temperature?

The short answer is no. This shift in blood supply throughout your body causes you to actually lose heat, but you don't notice because during this process you feel warmer. This is unlikely to cause you any health concerns when you are in a warmer environment. However, in cold settings this can cause problems.

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Alcohol induced hypothermia

As the alcohol education charity Drinkaware Trust warns, the combination of alcohol and very cold weather can be dangerous and even lethal. This is because your body's core temperature (regulated by the brain) and your body's shell temperature (influenced by the environment) are both under the influence of factors making it cooler.

Tipton describes what happens: "In cool air temperatures this heat loss can result in falling deep body temperature. In very cold air temperatures or cold water, the powerful cold stimuli at the skin override the alcohol-induced vasodilatation, and blood flow to the skin shuts down, defending deep body temperature."

Excessive drinking combined with the cold can lead to hypothermia, which occurs when your body temperature drops so low that it causes a cardiac arrest. A study of hypothermia and alcohol poisoning in adolescents found that in winter 26.6% of the intoxicated subjects experienced mild hypothermia. This was compared to 18.0% in the summer.

Thankfully, for most of us the chances of developing hypothermia are slim as long as we drink sensibly and avoid alcohol-induced bad decisions like going out in freezing weather. However, as the charity Homeless Link points out: "Rough sleepers and other members of the street population are at increased risk of hypothermia and frostbite."

Rough sleeping in extremely low temperatures over winter, combined with prevalent alcohol addiction problems, make the homeless population particularly vulnerable to hypothermia.

How to drink alcohol safely

To keep health risks from alcohol to a low level, it's important to follow the guidelines. The UK Chief Medical Officers’ Low Risk Drinking Guidelines advise that it is safest not to drink over 14 units a week. It is also recommended that you pace drinking alcohol evenly over three days or more. If you're pregnant, you should avoid alcohol altogether. The Drinkaware Trust provides a handy drink units calculator allowing you to track your units easily.

If you are looking to reduce your alcohol intake, the following methods may help:

• Designating alcohol-free days.

• Choosing bottles instead of pints, and small glasses instead of large ones.

• Tracking units by reading the label.

• Adding mixers to make your drinks last longer.

• Buying a measure so that you know how much you are drinking.

• Drinking a soft drink or a glass of water between alcoholic beverage .

• Avoiding salty foods while drinking, as these will make you want to drink more.

Alcohol addiction symptoms

You need to be able to identify the signs of alcohol addiction so that you can ask for help and start recovery. If you are concerned that you have become too dependent on alcohol, consult your GP. They can discuss your problem with you and arrange appropriate treatment.

Alternatively, there may be alcohol support services in your local area that you are able to access without a GP referral.

Somealcohol addiction symptoms and warning signs that indicate you have developed an alcohol dependency include the following:

• Having an overwhelming desire to drink.

• Having no interest in previously normal activities.

• Needing to drink more in order to achieve the same effects.

• Feeling tired, agitated or irritable.

• Feeling unable to say no to alcohol.

• Becoming secretive or dishonest.

• Pursuing the consumption of alcohol to the exclusion of other pleasurable activities.

• Continuing to drink despite clear evidence of harmful consequences.

If after stopping alcohol use, you are experiencing any of the below alcohol withdrawal symptoms, it may be pointing to alcohol use disorder or alcohol addiction:

• Hot flushes ranging from mild to physically dangerous.

• Craving alcohol.

• The 'shakes’ (trembling).

• Feeling sick.

• Irritability, anxiety, or agitation.

• Sweating.

• High blood pressure

• Increased heart rate

• Seizures.