Is it healthy to drink really cold water?

December 27, 2025 •

4 min read

According to one survey, 79% of people prefer drinking cold water, especially on hot days or after exercise, for its refreshing sensation. But beyond personal preference, is it healthy to drink really cold water, or are the associated health risks a cause for concern? This question has been debated for years, with arguments ranging from ancient Ayurvedic beliefs to modern scientific research.

Quick Summary

This article examines the scientific evidence behind drinking very cold water, weighing its potential benefits, like enhanced athletic performance and mild metabolism boost, against possible downsides for individuals with specific health conditions, such as achalasia or sensitive teeth. It also clarifies common myths surrounding cold water's effects on digestion and weight loss.

Key Points

Generally Safe: For most healthy people, drinking cold water is safe and does not cause significant health problems, as the body quickly regulates its temperature.
Exercise Aid: Consuming cooler water during exercise helps to lower core body temperature, which can improve athletic performance and endurance.
Mild Metabolism Boost: The body expends a small amount of energy to warm up ingested cold water, resulting in a minor, but insignificant, metabolic increase.
Specific Risks: Individuals with achalasia, sensitive teeth, or a propensity for migraines may experience pain or discomfort from drinking very cold water.
Personal Preference Matters: The most crucial aspect of hydration is consistent intake. The best water temperature for you is the one that encourages you to drink enough throughout the day.
Digestive Sensitivity: While not an issue for most, some people with sensitive stomachs may find that cold liquids cause temporary discomfort or digestive issues.

The Case for Cold Water: Performance and Metabolism

For most healthy individuals, drinking cold water is perfectly safe and can even offer certain benefits, particularly in specific scenarios like exercise or weight management. The body is remarkably efficient at regulating its core temperature, so any ingested cold water is quickly warmed to body temperature with minimal impact.

Exercise Performance

During high-intensity workouts or in hot environments, drinking cold water is a powerful tool for temperature regulation. Studies have shown that consuming cooler water during exercise can help maintain a lower core body temperature, delay the onset of fatigue, and improve endurance. The refreshing nature of cold water also encourages athletes to drink more, promoting optimal hydration. For athletes or those who work out regularly, this cooling effect can lead to a noticeable improvement in performance.

Mild Metabolic Boost

The theory that drinking cold water burns more calories is based on thermogenesis—the process where the body expends energy to warm up. While a small metabolic boost does occur, it's not a significant factor for weight loss. Some research indicates that drinking a cup of cold water may burn a handful of extra calories as the body works to raise its temperature. While this isn't a miraculous weight-loss solution, it's a minor benefit for those who prefer cold water.

Alertness and Low Blood Pressure

Some reports suggest that the shock of cold water can trigger a response that boosts adrenaline, leading to a temporary feeling of alertness. Additionally, for individuals with low blood pressure (hypotension), drinking cold water can induce a temporary increase in blood pressure due to vasoconstriction, the narrowing of blood vessels. In some cases, organizations like the Red Cross have suggested drinking water to raise blood pressure in hypotensive patients, with cold water having an equivalent effect to room temperature water.

Potential Risks and Who Should Be Cautious

While cold water is generally fine, certain groups and individuals with specific health conditions should be more mindful. The risks associated with cold water are typically short-lived and tied to how a person's body reacts to extreme temperatures.

Digestion and Stomach Sensitivity

Contrary to some myths, for most people, cold water does not harm digestion. The body quickly warms the fluid, and studies have not conclusively linked cold water to significant digestive issues. However, some individuals with sensitive stomachs or pre-existing gastrointestinal conditions may experience discomfort. For example, people with the rare esophageal disorder achalasia may find that cold water triggers chest pain and swallowing difficulties.

Respiratory Concerns

An older 1978 study found that drinking cold water temporarily thickened nasal mucus in some participants, which could exacerbate respiratory symptoms for those with a cold or flu. While this is not a universal effect, people experiencing congestion may find warm liquids more soothing.

Headaches and Dental Sensitivity

For some, particularly those prone to migraines, drinking very cold water quickly can trigger a headache. This is often called 'brain freeze.' Furthermore, individuals with pre-existing dental issues like gum disease, enamel loss, or cracks may experience a sharp, stabbing pain when drinking cold beverages.

Cold Water vs. Room Temperature Water: A Comparison


Feature	Cold Water	Room Temperature Water
Thermoregulation	Excellent for cooling the body during exercise or in hot weather.	Less effective for rapid body cooling during intense activity.
Metabolism	Provides a very minor, temporary boost to metabolism as the body warms the water.	No significant metabolic boost from temperature regulation.
Hydration	Often perceived as more refreshing, which can encourage increased intake.	Absorbed more quickly by the body, as it requires no warming.
Digestion	Can exacerbate symptoms for individuals with conditions like achalasia or a sensitive stomach.	May be gentler on the digestive system and is often recommended for sensitive stomachs.
Comfort	Highly refreshing and satisfying for many, but can cause 'brain freeze' or dental pain.	Generally neutral and avoids temperature-related discomfort.
Respiratory	Can thicken nasal mucus in some, potentially worsening cold symptoms.	Often recommended for sore throats and congestion as it does not cause vasoconstriction in the throat.

How to Drink Cold Water Safely

For most healthy adults, drinking cold water is a safe and effective way to hydrate. However, if you experience discomfort, consider adjusting your habits. To enjoy the benefits of cold water without risk, follow these best practices:

Drink in moderation: Avoid chugging large volumes of ice-cold water all at once. This reduces the risk of 'brain freeze' or temporary stomach discomfort.
Sip slowly: This allows your body to adjust to the temperature gradually. This is especially helpful if you have sensitive teeth.
Listen to your body: If drinking cold water causes pain, bloating, or any other negative symptoms, opt for room temperature or warm water instead. This is especially important for those with achalasia or other digestive issues.
Avoid extremes: Extremely cold or hot liquids are more likely to cause side effects. If you're concerned, a cool, but not icy, temperature is a great compromise.

Conclusion

While a glass of ice-cold water on a hot day is a simple pleasure for many, the debate over its health impact shows that context matters. For most healthy people, drinking really cold water is safe and can even offer benefits like improved athletic performance and a minor metabolic boost. The key takeaways are that extreme temperatures can trigger temporary symptoms like headaches or discomfort in sensitive individuals, and the body's natural thermoregulation largely neutralizes the temperature effect. Ultimately, the healthiest water temperature for you is the one you will drink consistently to stay hydrated without causing discomfort. Prioritizing overall hydration, regardless of temperature, remains the most important factor for long-term health.

For additional context on hydration, see this resource from the U.S. Army Research Institute of Environmental Medicine: Dehydration and Hydration in the Heat

Frequently Asked Questions

For most people, drinking cold water does not negatively impact digestion. The body is highly effective at regulating its internal temperature, and the water is warmed rapidly after consumption. However, individuals with certain pre-existing conditions, like achalasia, may experience temporary discomfort.

While drinking cold water causes your body to expend a tiny amount of extra energy to warm it up, this effect is too minor to have a significant impact on weight loss. The primary benefit of drinking water for weight loss is staying hydrated and feeling full, which helps reduce overall calorie intake.

Drinking cold water does not cause a sore throat. A sore throat is typically caused by viral or bacterial infections. However, the temporary vasoconstriction from cold liquids can sometimes cause irritation or exacerbate symptoms if you are already sick.

The sudden shock of extreme cold on the nerves in the palate and throat can cause what is known as 'brain freeze.' This temporary headache is more common in people who are already prone to migraines.

Yes, for athletes, cold water is often better than room temperature water, especially during intense workouts or in hot weather. It helps cool the body down more effectively, which can improve performance and encourage higher fluid intake to prevent dehydration.

Yes, if you have sensitive teeth due to conditions like receding gums or worn enamel, cold water can trigger sharp pain. In these cases, it's best to opt for room temperature or warm water to avoid discomfort.

In extreme circumstances where the elderly or children have a weakened immune system or are struggling to regulate body temperature, cold water could theoretically exacerbate 'cold stress'. For the majority of healthy individuals in these age groups, moderate intake is not harmful, but listening to one's body is key.