Heat Cramps, Exhaustion and Stroke

Dehydrated man

Our schools have let out for the summer, the weather is getting nice and it is time to get out and enjoy the great outdoors.

We might like to hike rugged trails, play ball with friends, enjoy the day at an amusement park with our kids and more! Summer time is for outdoor activities where we can live our lives to the fullest after the drudgery of a long cold winter. By following a few common sense precautions, every outing can be a blast! However, a few simple oversights can also lead a summer time outing into a catastrophic event that could alter your life forever, if it does not actually take it.

Note: of course what you are going to read also applies in the work place or other areas of our lives where we may be affected by heat. The following information is extracted from MayoClinic.org

Heat Cramps:

Heat cramps are painful, involuntary muscle spasms that usually occur during exercise in hot environments. The spasms may be more intense or more prolonged than are typical night time leg cramps. Fluid and electrolyte loss often contribute to heat cramps.

Muscles often affected include those of your calves, arms, abdominal wall and back. although heat cramps can involve any muscle groups involved in exercise. If you suspect heat cramps:

  • Rest briefly and cool down.
  • Drink clear juice or an electrolyte containing sports drink.
  • Practice gentle range of motion stretching and gentle massage of the affected muscle group.
  • Do not resume strenuous activity for several hours or longer after heat cramps go away.
  • Call your doctor if your cramps do not go away after an hour.

Note: severe muscle cramps that do not go away need medical attention as there may be another cause. For my personal example, severe cramps in my right leg were the result of a herniated disk in my spine at L5 S1 which caused permanent damage to my sciatic nerve. The result of this was very painful, intense muscle spasms similar to very bad heat cramps.

Heat Exhaustion:

Heat exhaustion is a condition whose symptoms may include heavy sweating and a rapid pulse, a result of your body overheating. Causes of heat exhaustion include exposure to high temperatures combined with high humidity, and strenuous physical activity. Without prompt attention, heat exhaustion can lead to heat stroke, a life threatening condition. Fortunately, heat exhaustion is preventable.

Signs and symptoms of heat exhaustion may develop suddenly or over time, especially with prolonged periods of exercise. Possible signs and symptoms of heat exhaustion include:

  • Cold, moist skin with goosebumps when in heat.
  • Heavy sweating.
  • Faintness
  • Dizziness
  • Fatigue
  • Weak, rapid pulse.
  • Low blood pressure upon standing.
  • Muscle cramps.
  • Nausea
  • Headache

If you are experiencing heat exhaustion:

  • Stop all activity and rest.
  • Move to a cooler place.
  • Drink water or a sports drink.

Contact your doctor if your signs or symptoms worsen, or if they do not improve within an hour. If you are with someone showing signs of heat exhaustion, seek immediate medical attention if he or she becomes confused or agitated, loses consciousness, or is unable to drink. You will need immediate cooling and urgent medical attention if your core body temperature 104 F or 40 C, or higher.

Cause of heat exhaustion

Your body’s heat combined with environmental heat results in your body’s core temperature. Your body needs to regulate the heat gain from the environment to maintain a core temperature that is normal, 98.6 F or 37 C.

In hot weather your body cools itself mainly by sweating. The evaporation of your sweat maintains your body temperature. However, when you exercise strenuously or otherwise over exert in hot, humid weather, your body is less able to cool itself efficiently. As a result, your body may develop heat cramps, the mildest form of heat related illness. Prompt treatment usually prevents heat cramps from progressing to heat exhaustion.

Besides hot weather and strenuous activity, other causes of heat exhaustion include:

  • Dehydration, which reduces our body’s ability to sweat and maintain a normal temperature.
  • Alcohol use which can affect your body’s ability to regulate it’s temperature.
  • Over dressing, particularly in clothes which do not allow sweat to evaporate easily.

Anyone can develop heat exhaustion, but certain factors increase your sensitivity to heat. They include:

  • Young or old age. Infants and children younger than 4 and adults older than 65 are at higher risk of heat exhaustion. The body’s ability to regulate its temperature is not fully developed in the young and may be reduced by illness, medications or other factors in older adults.
  • Certain drugs. Medications that affect your body’s ability to stay hydrated and respond appropriately to heat include some used to treat high blood pressure and heart problems (beta blockers, diuretics), reduce allergy symptoms (antihistamines), calm you (tranquilizers), or reduce psychiatric symptoms such as delusions (antipsychotics). Additionally, some illegal drugs, such as cocaine and amphetamines’, can increase your core temperature.
  • Obesity. Carrying excess weight can affect your body’s ability to regulate its temperature and cause your body to retain more heat.
  • Sudden temperature change. If you’re not used to the heat, you’re more susceptible to heat-related illness, such as heat exhaustion. Traveling to a warm climate from a cold one or living in an area that has experiences an early heat wave can put you at risk of a heat related illness because your body has not had a chance to get used to the higher temperatures.
  • A high heat index. The heat index is a single temperature value that considers how both the outdoor temperature and humidity make you feel. When the humidity is high, your sweat can’t evaporate as easily and your body has more difficulty cooling itself, making you prone to heat exhaustion and heatstroke, When the heat index is 91 F (33 C) or higher, you should take precautions to keep cool.

Preventing heat exhaustion/heatstroke

Untreated, heat exhaustion can lead to heatstroke, a life threatening condition that occurs when your core body temperature reaches 104 F (40 C) or higher. Heatstroke requires immediate medical attention to prevent permanent damage to your brain and other vital organs that can result in death. You can take a number of precautions to prevent heat exhaustion and other heat related illnesses. When temperatures climb, remember to:

  • Wear loose fitting, lightweight clothing. Wearing excess clothing or clothing that fits tightly won’t allow your body to cool properly.
  • Protect against sunburn. Sunburn affects your body’s ability to cool itself, so protect yourself with a wide brimmed hat and sunglasses and use a broad-spectrum sunscreen with an SPF of at least 15. Apply sunscreen generously and reapply every two hours, or more often if you are swimming or sweating.
  • Drink plenty of fluids. Staying hydrated will help your body sweat and maintain a normal body temperature.
  • Take extra precautions with certain medications. Be on the lookout for heat related problems if you take medications that can affect your body’s ability to stay hydrated and dissipate heat.
  • Never leave anyone in a parked car. This is a common cause of heat related deaths in children. When parked in the sun, the temperature in your car can rise 20 F in 10 minutes. It is not safe to leave a person in a parked car in warm or hot weather, even if the windows are cracked or the car is in the shade. When your car is parked, keep it locked to prevent a child from getting inside.
  • Take it easy during the hottest parts of the day. If you can’t avoid strenuous activity in hot weather, drink fluids and rest frequently in a cool spot. Try to schedule exercise or physical labor for cooler parts of the day, such as early morning or evening.
  • Get acclimated. Limit time spent working or exercising in heat until you’re conditioned to it. People who are not used to hot weather are especially susceptible to heat related illness. It can take several weeks for your body to adjust to hot weather.
  • Be cautious if you’re at increased risk. If you take medications or have a condition that increases your risk of heat related problems, such as a history of previous heat illness, avoid heat and act quickly if you notice symptoms of overheating. If you participate in a strenuous sporting event or activity in hot weather, make sure there are medical services available in case of a heat emergency.


Heatstroke is a condition caused by your body overheating, usually as a result of prolonged exposure to physical exertion in high temperatures. This most serious form of heat injury can occur if your body temperature rises to 104 F (40 C) or higher. The condition is most common in the summer months. Heatstroke requires emergency treatment. Untreated heatstroke can quickly damage your brain, heart, kidneys and muscles. The damage worsens the longer treatment is delayed, increasing your risk of serious complications or death.

Heatstroke signs and symptoms include:

  • High body temperature. A core body temperature of 104 F (40 C) or higher, obtained with a rectal thermometer, is the main sign of heatstroke.
  • Altered mental state or behavior. Confusion, agitation, slurred speech, irritability, delirium, seizures and coma can all result from heatstroke.
  • Alteration in sweating. In heatstroke brought on by hot weather, your skin will feel hot and dry to the touch. However, in heatstroke brought on by strenuous exercise, your skin may feel dry or slightly moist.
  • Nausea and vomiting. You may feel sick to your stomach or vomit.
  • Flushed skin. Your skin may turn red as your body temperature increases.
  • Rapid breathing. Your breathing may become rapid and shallow.
  • Racing heart rate. Your pulse may significantly increase because heat stress places a tremendous burden on your heart to help cool your body.
  • Headache. Your head may throb.

If you think a person may be experiencing heatstroke seek immediate medical help. Call 911 or your local emergency services number. Take immediate action to cool the over heated person while waiting for emergency treatment.

  • Get the person into shade or indoors.
  • Remove excess clothing.
  • Cool the person with whatever means available – put in a cool tub of water or a cool shower, spray with a garden hose, sponge with cool water, fan while misting with cool water, or place ice packs or cold, wet towels on the person’s head, neck, armpits and groin.

Heatstroke can occur as a result of:

  • Exposure to a hot environment. In a type of heatstroke, called nonexertional (classic) heatstroke, being in a hot environment leads to a rise in core body temperature. This type of heatstroke typically occurs after exposure to hot, humid weather, especially for prolonged periods. It occurs most often in older adults and in people with chronic illness.
  • Strenuous activity. Exertional heatstroke is caused by an increase in core body temperature brought on by intense physical activity in hot weather. Anyone exercising or working in hot weather can get exertional heatstroke, but it’s most likely to occur if you’re not used to high temperatures.

In either type of heatstroke, your condition can be brought on by:

  • Wearing excess clothing that prevents sweat from evaporating easily and cooling your body.
  • Drinking alcohol, which can affect your body’s ability to regulate your temperature.
  • Becoming dehydrated by not drinking enough water to replenish fluids lost through sweating.

Anyone can develop heatstroke, but several factors increase your risk:

  • Age. Your ability to cope with extreme heat depends on the strength of your central nervous system. In the very young, the central nervous system is not fully developed, and in adults over 65, the central nervous system begins to deteriorate, which makes your body less able to cope with changes in body temperature. Both age groups usually have difficulty remaining hydrated, which also increases risk
  • Exertion in hot weather. Military training and participating in sports, such as football or long distance running events, in hot weather are among the situations that can lead to heatstroke.
  • Sudden exposure to hot weather. You may be more susceptible to heat related illness if you’re exposed to a sudden increase in temperature, such as during an early summer heat wave or travel to a hotter climate. Limit activity for at least several days to allow yourself to acclimate to the change.
  • A lack of air-conditioning. Fans may make you feel better, but during sustained hot weather, air conditioning is the most effective way to cool down and lower humidity.
  • Certain medications. Some medications affect your body’s ability to stay hydrated and respond to heat. Be especially careful in hot weather if you take medications that narrow your blood vessels (vasoconstrictors), regulate your blood pressure by blocking adrenaline (beta blockers), rid your body of sodium and water (diuretics), or reduce psychiatric symptoms (antidepressants or antipsychotics). Stimulant’s for attention deficit hyperactivity disorder (ADHD) and illegal stimulants such as amphetamines and cocaine also make you more vulnerable to heatstroke.
  • Certain health conditions. Certain chronic illnesses, such as heart or lung disease, might increase your risk of heatstroke. So can being obese, being sedentary and having a history of previous heatstroke.

Heatstroke can result in a number of complications, depending on how long the body temperature is high. Severe complications include:

  • Vital organ damage. Without a quick response to lower body temperature, heatstroke can cause your brain or other organs to swell, possibly resulting in permanent damage.
  • Death. Without prompt and adequate treatment, heatstroke can be fatal!

Preventive measures for heatstroke are the same as for heat exhaustion.

Friends, enjoy the nice warm summer weather and please use good common sense when the weather gets really hot and humid. The life you save may be your very own, or that of a loved one.


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