Heat stroke is a medical emergency that occurs when the body can no longer cool itself. The body suffers from dehydration because it can’t release internal heat into the environment, resulting in core temperatures of over 104 degrees Fahrenheit. The scary part is that most people aren’t aware that they are in danger of heat stroke — the most severe heat-related illness — until it’s too late. And by then, they have become confused and delirious as a result of nerve damage. To reduce your risk of becoming ill, the first step is to become aware of heat stroke symptoms and the warning signs of heat-related illness. A quick diagnosis is crucial in order to avoid organ failure, cognitive impairment and death. (1)
But to ensure that your health is never put in harm’s way because of the heat, take preventative measures to keep your body cool and stay hydrated. It’s also important to avoid actions that increase your risk of developing heat-related illnesses, like engaging in physical activity that increases your chances of heat stroke, such as hot yoga and exercising in the direct sun.
What Is a Heat Stroke?
Heat stroke occurs when your body’s natural processes to regulate your core temperature begin to fail as you become overheated. Our bodies regulate our core temperature to maintain a constant temperature of 98.6 degrees Fahrenheit — even in the hottest or coldest environmental conditions. For this to be possible, our thermoregulatory system uses different physiological mechanisms in order to balance the heat produced inside the body and the amount of heat lost to the environment. When these mechanisms break down, heat stroke symptoms occur.
Did you know that you have temperature receptors in your skin? When the temperature outside the body becomes too high, the receptors send messages to the hypothalamus, which is the processing center in the brain. When the body becomes overheated, it releases heat by sweating and activating the muscles in your skin. Your blood vessels also begin to swell, or dilate, causing your skin to look red. More warm blood then flows close to the surface of your skin so that heat is lost through the skin and into the air.
Muscles in your skin work to increase heat loss by causing your hairs to lay down flat, as opposed to raising them up in order to trap more warmth. Your skin glands also secrete sweat onto the surface of your skin in order to increase heat loss by evaporation. Your body will keep sweating, releasing internal heat, until your body temperature returns to normal. (2)
The problem is when you sweat so much in an effort to cool down the body that you become dehydrated. When your body runs out of fluids to sweat out, and you haven’t been drinking enough water to supply more fluids, your body temperature will continue to rise. Then you may begin to notice heat stroke symptoms. Once your body’s core temperature rises, all of your innate processes that are in place to regulate your internal temperature break down, creating a serious problem.
Heat Stroke Symptoms
Before heat stroke symptoms develop, you will experience a few warning signs. Generally, heat-related illnesses occur in four stages: beginning with muscle cramping, leading to heat exhaustion and ending with heat stroke. Here’s a breakdown of these four stages (3):
1. Heat Syncope (fainting): Heat syncope, or fainting, occurs when your body tries to cool itself, which causes your blood vessels to dilate so much that blood flow to your brain is reduced. This usually occurs when a person has been working outside or has been physically active in a hot environment. Besides fainting, a person experiencing heat syncope may feel dizzy, restless and nauseous. (4)
2. Heat cramps: Heat cramps, also known as muscle cramping, is one of the first sign of heat-related illness. You may feel like you pulled a muscle, even though you weren’t doing anything strenuous. Muscle aches or cramping is a huge warning sign that you are dehydrated and need to get somewhere cool and drink water before your symptoms worsen.
3. Heat exhaustion: Heat exhaustion happens when the heat begins to make you feel uncomfortable and ill, leading to symptoms such as heavy sweating, weakness, headache, changes in pulse, cold, pale and clammy skin, nausea, vomiting and fainting. If left untreated, heat exhaustion can advance to heat stroke. (5)
4. Heat stroke: Heat stroke is the most serious of all heat-related illnesses. It is a medical emergency because it can lead to serious brain damage, organ failure and even death. The most common heat stroke symptoms include:
- body temperature above 103 degrees Fahrenheit
- rapid and strong pulse
- shallow breathing
- hot, red, dry or moist skin
- severe headache
- minimal or no sweating, despite the heat
- nausea and vomiting
- muscle weakness
- muscle cramps
- dark-colored urine
Heat stroke is so serious because it can lead to organ failure and even death. It immediately affects your cognitive function and can lead to impairment. In fact, research shows that approximately 20 percent of patients who suffer from heat stroke have long-term, irreversible brain damage as a result. (6) That’s why some of the most common heat stroke symptoms are delirium and confusion. Your nerve cells are particularly vulnerable when the body becomes overheated, and your brain is made up of these nerve cells. When the body overheats, the blood vessels dilate and blood flow increases, which strains the heart as well…