Heat Exhaustion Symptoms and Prevention

These are the heat exhaustion signs and symptoms everyone should know.

Maintaining a stable body temperature is crucial for the proper functioning of your body. The human body strives to keep its temperature within a narrow range, typically between 97°F to 99°F (36.1°C to 37.2°C), as indicated by the US National Library of Medicine. Usually, your body is adept at regulating its temperature effectively. However, there are instances, especially on sweltering, humid days, when this self-regulation mechanism may falter, putting you at risk of developing heat-related illnesses – a significant health hazard during the summer. According to the Centers for Disease Control and Prevention (CDC), heat-related illnesses pose a particular risk during outdoor activities, especially for individuals aged 65 and older or those taking medications that heighten sensitivity to high temperatures. Nevertheless, anyone can fall victim to these illnesses under the right conditions, even during other times of the year.

To help you stay safe and informed, we’ll explore the signs and symptoms of heat exhaustion and heatstroke, understand the key differences between these two conditions, and provide essential tips for preventing and addressing heat-related illnesses.

Heat Exhaustion vs. Heatstroke

When your body faces excessive heat and struggles to cool down efficiently, it can lead to heat exhaustion. According to the CDC, during heat exhaustion, the body’s core temperature remains below 104°F, blood pressure drops, and the heart loses some of its efficiency in pumping blood.

At this stage, the body is still attempting to self-regulate, and natural defense mechanisms are active. Dr. Peter Shearer, Associate Director of the Mount Sinai Hospital Emergency Department in New York City, explains, “You’ll experience significant fatigue, profuse sweating, and an increased thirst – these are your body’s natural responses to combat heat and dehydration.”

It’s important to note that heat exhaustion does not necessarily progress to heatstroke, but it can. Heatstroke, described by exercise physiologist Michael Bergeron, PhD, as a “clear medical emergency affecting multiple body systems,” typically occurs when the body’s core temperature exceeds 104°F.

A 2022 review published in Experimental Physiology indicates that heatstroke disrupts the central nervous system and can cause damage to vital organs such as the brain, heart, liver, kidneys, spleen, and muscular tissue. Dr. Shearer adds, “During heatstroke, the body loses its ability to thermoregulate, making it significantly more challenging to reverse the condition.”

Recognizing Warning Signs: Cramps, Nausea, or Headaches

The initial indicators of heat-related illness often manifest as stomach cramps or nausea, which may signal dehydration or an electrolyte imbalance, says the CDC. These symptoms are closely linked to heat illnesses because the body requires water and electrolytes, like sodium, to effectively manage its temperature. However, these essential elements are lost through sweat, which can lead to electrolyte imbalances and dehydration. Additionally, headaches are a common early sign of dehydration.

It can be challenging to pinpoint the exact cause of gastrointestinal distress during physical activity. As Michael Bergeron advises, “If you suspect heat-related factors may be involved, it’s best to assume so and take a break to hydrate.” You should only resume activity once you feel better.

Recognizing Warning Signs: Thirst and Heavy Sweating

“Heavy sweating is an indication that your body is generating excess heat,” explains Bergeron. This excessive heat production could lead to heat exhaustion if conditions do not improve or worsen. A 2020 research article published in the Medico Legal Journal highlights the increased danger of heat on humid days. In such conditions, sweat cannot evaporate easily, making it harder for your body to cool down as it typically would in dry or breezy weather.

Feeling thirsty is another sign that your body requires more hydration. Even if you don’t sense extreme thirst, it’s essential to sip water frequently on hot days. If you anticipate being exposed to the heat for over an hour, consider using a sports drink to replenish lost electrolytes.

Recognizing Warning Signs: Dark Urine

Monitoring your urine can provide essential insights into your hydration status. Dr. Shearer explains, “If you’re participating in an activity like tennis for hours, staying hydrated between sets, taking regular bathroom breaks, and your urine remains relatively clear, that’s a positive sign of proper hydration.” However, if you engage in strenuous exercise, and your urine is infrequent, dark, and concentrated, it’s a clear indication of dehydration. This means your body may struggle to release heat efficiently through sweat and evaporation, increasing your risk of overheating.

Recognizing Warning Signs: Dizziness or Collapse

Heat exhaustion frequently leads to sensations of dizziness, prompting the need to sit down or even momentarily passing out. According to Bergeron, this is a protective response, as it prevents individuals from continuing strenuous activity before facing more severe consequences. Dizziness may be accompanied by tachycardia (rapid heart rate), and individuals may experience syncope (brief loss of consciousness).

It’s important to note that these symptoms become more common as the temperature rises. However, strenuous workouts in relatively cool conditions can also lead to exertional heat illnesses.

Recognizing Warning Signs: Lack of Sweating

As the body’s internal temperature rises, its natural cooling mechanisms, such as sweating, may begin to shut down. Dr. Shearer highlights, “If you’ve been exercising outdoors in the heat, and your skin is entirely dry, that’s a red flag.” However, Bergeron emphasizes that the absence of sweating doesn’t guarantee safety – if other signs of heat illness are present, it’s crucial to seek immediate help.

Recognizing Warning Signs: Confusion, Convulsions, or Coma

Heatstroke, when left untreated, can severely impact brain function. Dr. Shearer notes, “Confusion and delirium are telltale signs of advanced heatstroke.” In this state, individuals may struggle to make rational decisions to cool themselves down, such as seeking shade or water.

In severe cases of heatstroke, fainting and convulsions can occur. Importantly, these signs and symptoms may not necessarily align with the sensation of feeling hot. Bergeron explains that during the early stages of overheating, individuals may even feel chilled, thanks to the body’s production of inflammatory proteins, as described in a 2022 review in Nature Reviews Disease Primers. These proteins can disrupt the body’s thermoregulation, leading to sensations like chills, goosebumps, or cold, clammy skin.

The Challenge of Self-Assessment

Recognizing the onset of heat illness can be challenging, especially for individuals engaged in intense physical activity. Bergeron points out that as the body and brain heat up, cognitive capacity and objective reasoning often become compromised. Therefore, an overheated athlete is not always the best judge of their condition.

What to Do: Listen to Your Body

The majority of your body’s heat production arises from muscle exertion. In hot and humid conditions, it’s wise to reduce the intensity of your workout and take precautions such as wearing moisture-wicking clothing and staying well-hydrated. If you start to feel overheated, Michael Bergeron advises, “Stop your activity immediately.” He emphasizes that significant performance deterioration or any signs of struggling should serve as a clear signal to take a break.

What to Do: Seek Shade or Cool Environments

If you or someone you’re with begins experiencing symptoms of heat illness, the first step is to get out of the sun. Ideally, you should find an air-conditioned area. However, any shaded spot can provide relief. According to the U.S. Occupational Safety and Health Administration, direct sunlight can result in a heat index up to 15 degrees higher than in a shaded area nearby.

What to Do: Enhance Air Circulation

Boosting air circulation and allowing air to flow over the skin can assist in cooling down. Dr. Shearer suggests loosening clothing to avoid any constriction and using a fan, whether manual or electric, to help dissipate excess body heat.

What to Do: Elevate Legs

Heat illness can impede blood flow throughout the body. Sitting or lying down with your legs elevated about 12 inches can help prevent leg swelling and enhance blood flow to the brain, as per a 2022 review in Experimental Physiology. This measure also reduces the risk of fainting and subsequent injuries.

What to Do: Hydrate and Cool the Body

If an individual is conscious and able to swallow, encourage them to drink cold water or a sports drink containing electrolytes. The CDC recommends cool fluids in such cases. In case you don’t have a sports drink on hand, you can make your own electrolyte solution by dissolving a teaspoon of salt per quart of water. Sipping on these fluids can help replenish lost sodium due to sweating and assist in cooling the body.

Using cold water or ice to cool down is also effective, but avoid placing ice directly on the skin. For individuals not sweating, spraying them with water can mimic the cooling effect of evaporation. In cases where body temperature reaches dangerous levels, full-body immersion in an ice bath or a cold body of water is the most efficient method to rapidly reduce body temperature, says Bergeron. Applying ice packs or cold-water-soaked towels to the body can also provide relief. Effective areas for cooling include the groin, armpits, palms of the hands, soles of the feet, and the forehead. However, Dr. Shearer advises against placing ice packs directly on the neck, as it contains the carotid artery that supplies blood to the brain.

Seek Medical Assistance

If someone displays signs of heatstroke, it’s crucial to seek immediate medical attention. Monitoring blood pressure, temperature, heart rate, respiratory rate, and central nervous system status is essential, even when symptoms appear to improve.

On the other hand, heat exhaustion may not always require professional medical attention. Dr. Shearer notes, “Young, healthy individuals who remain sweaty and clear-headed will often recover with rest and cooling.” However, for older individuals or those with underlying medical conditions like heart disease or diabetes, it’s safer to seek medical evaluation.

Post-Illness Recovery

Even if you recover from a heat-related illness, it’s vital not to immediately resume strenuous activities. According to Bergeron, dehydration and a risk of rapid overheating may persist. He recommends taking the rest of the day off from physical exertion, even if you feel completely better. “It’s better to rest and allow your body to recover fully,” he emphasizes.

Prevention Is Key

Preventing heat-related illnesses is far more manageable than treating them, considering the potential severity of these conditions. To minimize the risk:

1. Avoid High-Risk Situations: Stay away from activities that expose you to extreme heat, especially if you are recovering from conditions involving vomiting, diarrhea, fever, or taking medications that increase heat sensitivity.

2. Gradual Acclimation: If you plan to exercise in hot weather, consider gradually ramping up your workouts over several weeks. This allows your body to acclimate to higher temperatures, reducing the risk of overheating during the summer.

3. Hydration: Maintain proper hydration levels by drinking water regularly, even if you don’t feel thirsty. On longer outings in the heat, consider using sports drinks to replenish lost electrolytes.

4. Appropriate Attire: Wear lightweight, breathable clothing, and use moisture-wicking fabrics that help keep your body cool. Don’t forget to protect yourself from direct sunlight with hats and sunglasses.

5. Listen to Your Body: Pay close attention to your body’s signals and respond promptly to any signs of overheating or discomfort.

In conclusion, recognizing the signs and symptoms of heat exhaustion and heatstroke and taking appropriate measures to prevent them is essential for staying safe during hot weather. Remember that heat-related illnesses can affect anyone, so being proactive and prepared is the key to enjoying outdoor activities safely, even in the most scorching temperatures. Stay cool, stay hydrated, and stay informed to protect yourself and those around you from the dangers of heat-related illnesses.