Alcohol, Dehydration and Water Safety With Temperature Exposure

Urgent help comes first

Someone who has passed out in a sauna, bath, hot tub or cold water, cannot be woken, or has stopped breathing needs emergency help now. In the United States call 911 or the local emergency number. [1] Drowning can happen quickly. [2] Do not leave a person who has been drinking alone in hot water or near water. This page is general information, not medical advice. It gives no temperatures, times or routines, and it does not cover breath-holding or breathing-practice combinations with water.

Alcohol and heat

Alcohol and heat is a combination with a long record of harm. A paper on the sauna and alcohol reported that, in Finland, alcohol was estimated to be a contributing factor in some 20 to 25 sauna-related deaths every year. [3] It also described minor accidents such as sprains and burns, and more serious ones such as head injuries, heat stroke after passing out in a sauna and drowning while swimming. [3]

The authors said that large amounts of alcohol while sauna bathing may affect the body's ability to maintain blood pressure, and that a drop in blood pressure on standing is more likely, with fainting and accidents. [3] They were also frank that the scientific information on the interaction of sauna and alcohol on human physiology was lacking, so their discussion rested largely on presumptions. [3] That paper is from 1988, so it is background, not new data.

A later review of sauna benefits and risks concluded that alcohol consumption during sauna bathing increases the risk of low blood pressure, abnormal heart rhythm and sudden death, and should be avoided. [4] A review on sudden cardiac death attributed rare sauna-linked cases to dehydration, low blood pressure and heart rhythm problems from sauna exposure combined with alcohol. [5]

Hot tubs and baths

A review of hot-tub deaths looked at physical factors including blood circulation changes and the role of alcohol and substances. [6] In the United Kingdom, a study of coroners' records of drug-related deaths in a bath or hot tub found that polysubstance, opioid and alcohol use were overrepresented, and it suggested advice to avoid bathing while intoxicated. [7] In Japan, home hot-tub bathing substantially increases drowning mortality rates among older adults. [8]

These are reports of patterns, not a measure of how likely any one person's risk is.

Dehydration

Dehydration is one cause of fainting. [9] MedlinePlus lists drinking alcohol among things that can raise the risk of heat illness. [10] The NHS advice for preventing heat exhaustion and heatstroke includes avoiding drinking too much alcohol. [11] Heat stroke is a life-threatening illness. [10]

This page does not say how much to drink or when. That depends on health, medicines and conditions such as heart or kidney disease, which a doctor should discuss with you. Sports drinks, salt products and supplements marketed for hydration are not covered here.

Water safety with cold and warm water

The World Health Organization defines drowning as the process of experiencing respiratory impairment from submersion or immersion in liquid. [12] It reports that higher drowning rates among males are linked in studies to increased exposure to water and riskier behavior such as swimming alone and drinking alcohol before swimming alone. [12] MedlinePlus lists not swimming or boating while under the influence of alcohol or sedatives among drowning precautions. [2] A survey of young Australian men calls alcohol a significant risk factor for drowning. [13]

Cold water adds its own risk. The sudden gasp and rapid breathing of cold shock raise drowning risk even for confident swimmers in calm water. [1] Cold shock can also cause panic that impairs clear thinking and decision making. [1] A life jacket significantly increases the chance of survival in unplanned cold-water immersion. [1] The British Heart Foundation advises not swimming alone, but going with a friend or a group. [14]

Who is most affected

The NHS lists accidents causing injury and sometimes death among the risks of drinking too much alcohol. [15] People who take medicines that cause drowsiness or affect blood pressure, older adults, people with heart conditions and anyone unwell are better off asking a doctor or pharmacist first. See Temperature Exposure and Cardiovascular Conditions and the Natural Remedy Safety page on how interactions work.

The bottom line

The safest approach supported by these sources is simple. Avoid alcohol around heat and cold water, do not do either alone. For what each practice involves, see Saunas and Steam Rooms, Cold-Water Immersion, Cold Showers and Contrast-Water Practices, and Temperature Exposure Safety: Cold Shock, Fainting and Burns.