Heat exhaustion: Causes, Symptoms and Treatment

Heat stress is not just the leading cause of weather-related deaths, but it can also make people’s underlying health issues worse, according to the World Health Organization. Global climate change has boosted the number of people exposed to extreme heat, increasing heat-related mortality for people over 65 years of age by approximately 85 percent between 2000–2004 and 2017–2021, notes WHO. These are alarming figures, and necessitate greater understanding of heat-related issues such as heat rash, heat cramps, heat exhaustion and heat stroke.

If you step out too much in the sun when the temperature soars high, it will be natural to start sweating and feeling dehydrated. Heat exhaustion is a common concern in peak summer season, and its severity can range from mild to maybe life-threatening.

What is heat exhaustion?

Heat exhaustion is the body’s response to excessive loss of water and salt through excessive sweating, says physician and intensivist Dr Roohi Pirzada.  The causes of heat illness include exposure to high temperatures, especially when there is also high humidity and physical activity of moderate intensity. Heat exhaustion also has three levels – heat cramps, heat exhaustion and heat stroke.
If you live in hot climates it is essential to know how to identify symptoms of heat emergencies.

Heat exhaustion can last 24 to 48 hours depending on severity, and sometimes may need hospitalization to monitor fluid electrolyte balance and vital parameters.

Types of heat exhaustion

Heat exhaustion is of two types:

1. Water depletion
Heat exhaustion can translate to signs of extreme thirst, weakness, headaches, or even loss of consciousness.

2. Salt depletion
Some of the symptoms of low salt include feelings of nausea or vomiting, muscle cramps, and dizziness.

Even though the gravity of heat exhaustion isn’t as severe as heat stroke, it should be treated well. If left unattended, heat exhaustion can progress to stages of heat stroke that can harm the brain or other important organs.

Also read: Heatwave can cause digestive problems! 8 ways to protect your stomach

Symptoms of heat exhaustion

Some of the most common signs of heat exhaustion include:

• Lack of clarity
• Dark-coloured urine (a sign of dehydration)
• Dizziness
• Swooning
• Tiredness
• Headache
• Muscle cramps
• Nausea or diarrhoea
• Pale skin
• Excess sweating
• Cool moist skin
• Weak rapid pulse
• Low blood pressure

Causes of heat exhaustion

Heat exhaustion happens when the body is unable to regulate internally generated heat from metabolic processes, and reduce heat gain from external sources such as the environment.  The body’s inability to regulate internal temperature typically increases the risk of heat exhaustion and heatstroke.

Heat exhaustion can happen due to the following causes:

1. Due to the body’s inability to cool itself

In extremely hot weather, our body stays cool by the process of sweating. Our body temperature is regulated by the evaporation of sweating. However, if we overexert ourselves by indulging in vigorous exercise or otherwise in this hot, humid weather, then our body loses its ability to cool itself. This can give rise to heat cramps in the body. Heat cramps have very little severity in terms of heat-related illness. Excess sweating, tiredness, thirst, or muscle cramps are some of the symptoms of heat cramps. Quickly treating these symptoms can stop heat cramps from progressing to other grave heat illnesses like heat exhaustion.

2. Dehydration

When we do not amp up our fluid intake in such hot weather, we have a higher chance of getting dehydrated. And, dehydration lessens the ability of our body to sweat to maintain its normal temperature.

3. Alcohol consumption

Alcohol dehydrates our body, reducing our body’s ability to sweat and maintain its average temperature.

4. Overdressing

When we layer up more clothes than required in hot weather, such clothes do not allow the sweat to release and evaporate from our bodies. This again hinders the process of our body to maintain a healthy temperature.

Risk factors of heat exhaustion

Anyone can suffer from heat exhaustion, but certain factors make some people more prone to suffer from such heat-related illnesses.

1. Young age or old age

Infants who are below the age of 4 or adults who are 65 years or older are at a higher risk of heat exhaustion. Infants do not have a strong immunity to be able to regulate temperatures, while older people suffer from certain illnesses or consume certain medications that hinder their body’s ability to control temperature.

2. Certain medications

Some medications that are used to treat blood pressure, and heart problems, curb allergy symptoms, calm you or lower psychiatric symptoms can increase your body’s core temperature.

3. Obesity

Having excess body weight hinders our body from maintaining its ideal temperature, causing our body to allow more heat in.

4. Sudden changes in temperature

When we suddenly shift from a very cold climate to a hot one, our body is not given time to adapt to the new temperatures and that puts us at a higher risk of getting heat exhaustion.

How to treat heat exhaustion?

Fortunately, heat exhaustion is treatable. Here are some ways to treat it:

1. Common measures

The risk of heat-related illness dramatically increases when the heat index climbs to 90 degrees or more, says the expert. In those cases, a person can adopt the following measures himself:

• Pay attention to heat indices
• Use hats and caps outdoors. Wear lightweight and loose-fitted clothes
• Stay indoors during peak heat hours
• Avoid heavy sports or strenuous physical activity that can lead to excess sweating and dehydration
• Drink plenty of fluids like water or sports drinks
• Try cooling measures like taking a cool bath or shower. If you are outdoors, you can look for a water body like a pond or stream that can help drop your body temperature
• Hop into an air-conditioned building, use shade areas to stand and wait, or sit in front of the fan

2. Help cool the person

If someone you know is suffering heat exhaustion, lay the person down and raise his or her legs and feet slightly. Remove tight clothing or heavy clothing. Have the person sip chilled water sports drinks or non-alcoholic beverages without caffeine. Cool the person by spraying or sponging with cool water and fanning, suggests the expert. If measures fail within 15 to 30 minutes, seek medical help.

Also read: Ayurveda expert shares 3 unique ways to conquer the summer heat

If the above measures fail, your healthcare provider may advice the following measures for heatstroke treatment.

1. Cold water bath

A bath in ice-cold water is one of the most effective ways to lower body temperature. The quicker this remedy is followed, the less will be damage to the body’s organs or death.

2. Evaporation cooling techniques

If the cold water method fails to show results, the health care team can make use of the evaporation method to lower body temperature. In this method, cool water is sprayed on the body while fanning warm air over you. This helps the water to evaporate and thus cool down your body.

3. Covering you with ice or cooling blankets

Your healthcare team can wrap you in a special cooling blanket. Alongside, ice packs can be applied to your organs like the neck, groin, back, and armpits.

4. Medications

If treatments are not showing results, doctors can prescribe muscle relaxants that can stop shivering in the body. Shivering lessens the effectiveness of the treatments.