Nutrition Diet: What not to drink in extreme heat?

October 8, 2025 •

4 min read

According to the Centers for Disease Control and Prevention (CDC), dehydration is a primary contributor to heat exhaustion and heatstroke. When facing scorching temperatures, our choice of beverages is critical. Many popular drinks can actually be counterproductive, so it's vital to know what not to drink in extreme heat?

Quick Summary

This article explains which beverages—including alcohol, caffeinated drinks, and high-sugar sodas—can worsen dehydration during hot weather. It covers the science behind their dehydrating effects and offers safer alternatives for staying properly hydrated.

Key Points

Avoid Alcohol: It is a powerful diuretic that accelerates fluid loss and hinders your body's ability to regulate its temperature.
Limit Caffeine: Excessive intake of coffee, tea, and energy drinks can have a diuretic effect, increasing urination and risking dehydration.
Ditch Sugary Drinks: High-sugar sodas and juices can worsen dehydration by pulling water from your body during digestion.
Opt for Water: Cool, plain water is the best and most effective way to hydrate and cool your body during extreme heat.
Choose Natural Alternatives: Coconut water and herbal iced teas are excellent choices for replenishing lost fluids and electrolytes.
Recognize Dehydration Signs: Pay attention to signs like dark urine, fatigue, and dizziness, and drink water before you feel thirsty.

The Dehydration Trap: Why Your Body Needs the Right Fluids

During periods of extreme heat, your body's natural cooling mechanism kicks into high gear. Sweating is the primary way your body releases heat, but this process also depletes your fluid and electrolyte levels. If not replenished properly, this can quickly lead to dehydration, a dangerous condition that can escalate into heat exhaustion and heatstroke. While the instinct might be to reach for a cold beverage, not all drinks are created equal when it comes to effective rehydration. Some, in fact, can actively work against your body's efforts to stay cool and hydrated.

The Dangers of Diuretics: Alcohol and Caffeine

One of the most critical categories of drinks to avoid in extreme heat are those that act as diuretics, meaning they increase your body's production of urine, accelerating fluid loss.

Alcohol

Alcohol is a major culprit for dehydration during a heatwave. It is a powerful diuretic that interferes with your body's ability to regulate its temperature. In hot weather, where you're already losing significant fluid through sweat, consuming alcohol can lead to rapid and dangerous dehydration. Furthermore, alcohol can impair judgment, increasing the risk of heat-related illness. It's best to avoid alcoholic beverages entirely when temperatures soar.

Caffeinated Drinks

Coffee, tea, and energy drinks all contain caffeine, a mild diuretic that can increase urine output. While a single cup for a regular coffee drinker might not cause significant dehydration, excessive consumption can be counterproductive during a heatwave. Energy drinks, in particular, are problematic due to their often very high caffeine and sugar content, which puts extra strain on the heart during hot weather.

The Problem with Added Sugars: Sodas and Fruit Juices

Another category of drinks to avoid are those loaded with added sugar. While a cold soda or a sweetened fruit juice might seem refreshing, the high sugar concentration can pull water from your body into your small intestine to dilute it, a process that can worsen dehydration. These beverages offer empty calories and can lead to energy crashes, making you feel more fatigued in the heat. Natural fruit juices can also be high in sugar and are best consumed in moderation or diluted with water.

The Misconception of Sports Drinks

For most people, sports drinks are not necessary during a heatwave and can be more harmful than helpful. While they are designed to replace electrolytes lost during prolonged, intense exercise, many contain excessive sugar and sodium. The high sugar content can impede proper hydration, and for someone who is simply trying to stay cool, the extra calories are unnecessary. Water is the best choice for general hydration. For significant, multi-hour sweat loss, such as for athletes or outdoor workers, a sports drink might be beneficial, but it should be consumed carefully.

Healthier Alternatives for Optimal Hydration

Instead of reaching for dehydrating beverages, opt for these hydrating alternatives:

Plain Water: The gold standard for hydration. Drink cool water consistently throughout the day, not just when you feel thirsty.
Infused Water: Add flavor to your water with slices of cucumber, lemon, berries, or mint for a refreshing twist without the added sugar.
Coconut Water: A natural source of electrolytes like potassium, it can be a great way to replenish minerals lost through sweat.
Herbal Iced Teas: Brew caffeine-free herbal teas like peppermint or hibiscus, then chill them. They are naturally cooling and soothing.
Buttermilk (Lassi): In many cultures, buttermilk or lassi is consumed to cool the body. It provides probiotics and helps regulate body temperature.

Comparison of Dehydrating vs. Hydrating Beverages


Feature	Dehydrating Drinks	Hydrating Drinks
Mechanism	Act as diuretics, increase urination, and draw water from body tissues.	Replenish fluids directly without causing increased water loss.
Sugar Content	High in added sugars, which can worsen dehydration.	Typically low in sugar or naturally sweetened.
Electrolyte Balance	Often contain inappropriate levels of electrolytes for general use, or none at all.	Contain natural electrolytes (like coconut water) or can be easily balanced with food.
Calorie Count	High in empty calories from sugar.	Generally calorie-free or very low in calories.
Ideal For	Very specific, high-intensity athletic scenarios (sports drinks) or avoided entirely (alcohol).	Daily consumption and during heat exposure for most individuals.

Staying Safe and Hydrated

Staying properly hydrated is more than just drinking a lot of fluid; it’s about choosing the right fluids to support your body's temperature regulation. During extreme heat, a beverage can be your best friend or your worst enemy. By avoiding diuretics and high-sugar drinks, you can help prevent heat-related illnesses and maintain your health.

Conclusion

When temperatures rise, your body relies on proper hydration to function correctly and cool itself effectively. Avoiding beverages that cause dehydration—namely alcohol, excessive caffeine, and sugary sodas—is a crucial step in preventing serious health issues. Instead, prioritize plain water and other naturally hydrating, low-sugar options like coconut water and herbal teas. By making informed choices about what you drink, you can better protect yourself and enjoy a safer, healthier summer.

Additional Resources

For more information on preventing heat-related illness, consult the CDC's resources on extreme heat.

Frequently Asked Questions

While diet soda doesn't contain sugar, it's still best to limit it. The artificial sweeteners and carbonation offer no nutritional benefit and can lead to bloating, while plain water remains the most effective hydration method.

Sports drinks are not necessary for general hydration. They are specifically formulated for athletes engaged in prolonged, high-intensity exercise to replace electrolytes. For most people, the high sugar content can be counterproductive.

Coconut water is an excellent option as it is rich in natural electrolytes like potassium. Herbal iced teas (caffeine-free) and diluted fruit juice can also be good choices.

Alcohol acts as a diuretic, causing your body to excrete more water than it takes in. This effect is compounded in hot weather when you are already losing a significant amount of fluid through sweat, leading to a higher risk of dehydration.

Common signs of dehydration include extreme thirst, dark-colored urine, infrequent urination, fatigue, muscle cramping, and lightheadedness. It's best to drink water proactively and not wait until you feel thirsty.

Both hot and iced coffee/tea contain caffeine, which is a diuretic. While some people are accustomed to it, it's generally best to limit caffeine intake during a heatwave and focus on water to avoid increasing fluid loss.

Drinking too much plain water without adequate salt intake can lead to a medical emergency by causing the concentration of salt in the blood to become too low. It's important to balance fluid intake with electrolytes, which are usually replenished through regular meals.