In the outdoor setting, some of the most common emergencies are heat related. These emergencies can be prevented with a little knowledge and preparedness. If a heat illness is unrecognized or left intreated, it can easily progress in to a life threatening emergency. Below you will find causes of heat related injuries, signs and symptoms, and treatment for common heat injuries/ illnesses.
*Disclaimer*
Before we go any further please know that I have done my best to provide the most accurate information available. Though I am a Nationally Certified WEMT, it is a hobby of mine and not a working career. Please use this article for information and awareness and seek professional medical help and advice when needed.
Causes:
Excessive dehydration from sweating and salt loss( without replacement) in a warm environment to the extent that the sweating mechanism can no longer function.
Environments with high humidity where sweat cannot evaporate off the skin( causing the cooling effect to be lost)
Exercising in a hot environment without taking precautions or recognizing early warning signs.
Contributing factors:
Age( the very young or very old are more susceptible)
Poor health
Use of certain medications
Prior history of heat illness
Heart disease
Fatigue
Alcohol consumption
Overexertion in a hot environment
Dehydration signs and symptoms
Headache and mild nausea
Irritability
Dark urine
Thirst
Dehydration treatment
1.Rehydrate with water and electrolytes by using a pre made solution like gatorade.
2.An improvised solution can be made by mixing 1tsp salt, 8tsps sugar and 1 liter of water.
3. Pre made oral rehydration solution(ORS)
4. Adding 1/2 a banana or 1/2 cup of orange juice to help supply potassium.
5.Maintaining hydration for the long term.
Heat Cramps signs and symptoms
Muscle pain and cramping, usually in the legs, caused by dehydration and electrolytes depletion.
Usually occurs after exercise.
Heat Cramps Treatment
Same as dehydration
Heat Exhaustion
Caused by working in a hot environment.
Is a combination of salt and water loss secondary to sweating in hot conditions.
Typically occurs in people who are not acclimatized to heat.
Those not use to working in a hot environment will lose salt more rapidly than someone whose physiology has adjusted to working in hot conditions.
Sodium plays an important role in maintaining cell wall integrity and membrane permeability, and is essential in maintaining normal homeostasis on a cellular level. If the amount if sodium in the extracellular fluid decreases, system wide cellular dysfunction will occur, causing flu-like or exhaustion symptoms.
Heat exhaustion is not a life threatening emergency: it is relived by rest, hydration, and electrolyte replacement.
Heat Exhaustion Signs and Symptoms
Fatigue
Thirst
Possible dizziness
Increased heart rate
Increased respiratory rate
Pale, clammy skin
Muscle cramps
Nausea without vomiting
Minor mood changes that can vary from a simple headache and slight anxiety to agitation and confusion.
Heat Exhaustion Treatment
Rest in a cool place
Find shade if possible
Remove excess clothing that may trap heat.
Apply cool cloths to body( e.g.damp bandanna).
Replace lost fluid and salt at least 1 -2 liters of oral rehydration solution.
Monitor body temperature
The patient should recover within 6-8 hours.
If the symptoms of heat exhaustion are ignored and the person continues to work and sweat hard, it can progress to heat stroke.
Heat stroke
Heat stroke is a life-threatening emergency.
If not treated immediately, it will quickly progress to coma and death.
The time from the onset symptoms to death can be as little as 15 minutes after the sweating mechanism fails and the core temperature begins to rise.
For those who survive, heat stroke can cause permanent disability.
Remember that heat stroke is always preventable. But it gets going, it is almost impossible to stop outside of an emergency department.
Heat stroke types
Classic
Dehydration in a hot environment caused by the person "over- sweating" without replacing lost fluids, which leads to the failure of the sweating mechanism, causing the core temperature to rise rapidly.
The patient is losing water faster than they are replacing it.
Once the sweating mechanism fails, cooling stops and the core temperature rises rapidly.
Exertional
Exercising in a hot and high humidity environment where the sweat mechanism cannot function because the sweat cannot evaporate; again, the core temperature rises rapidly. the sweat, even though copious, cannot evaporate fast enough, and the patient overheats.
Heat stroke pathology
Brain: encephalopathy ( swelling of the brain)
Liver: injury is common and the liver is most susceptible to early damage. Note: the liver is normally 2 degrees F warmer than the rest of the body so it has less of a temperature buffer and permanent damage is possible( and can occur faster).
Kidneys: renal failure is common.
Muscles: damage results from rhabdomyolysis( the rapid breakdown of skeletal muscle due to injury to the muscle tissue)
Blood: coagulopathy( clotting disorders) due to disseminated intravascular coagulation (DIC) is common.
Death occurs when the core temperature exceeds 107 degrees/41.6 degrees - the point at which the tissues of the brain are destroyed.
Heat stroke signs and symptoms
Patient will be red, hot, and mad due to vasodilation as the body tries to deal with the increase in core temperature.
The skin will be red, hot and dry( classic) or sweaty( exertional).
The patient cannot sweat because they are dehydrated or because evaporation is impossible(i.e. High humidity).
The patient will be disoriented, confused, combative, and may hallucinate wildly. These changes are caused by core temperatures above 104F/40C.
The patient may have seizures
The patient may not be able to urinate.
The patient will have increased heart and respiratory rate.
Heat stroke treatment
Heat stroke needs to be recognized early and treated aggressively. The duration and degree of temperature elevation determines the level of organ damage and the ability for the patient to recover.
1. Remove patient from heat and sun and place in a cool, shady place.
2. Remove clothing down to underwear.
3. Cool them immediately by soaking with cool water and fanning to accelerate evaporation.
4. Vigorously massage limbs to encourage hot blood to flow to extremities where it can cool.
5. Beware of shivering. Shivering produces heat. If the patient begins to shiver, stop cooling them until they stop shivering, then resume cooling at a less aggressive rate.
6. Hydrate once conscious.
7. Do not allow patient to exercise.
8. Evacuated immediately to definitive care ( do not let patient walk out on their own)
9. Continue cooling during transport.
Other treatments require a medical professional and will not be covered.
Prevention
Maintain adequate fluid and electrolyte intake.
Monitor the group for fluid and electrolyte intake.
Be aware of changing environmental conditions, allow time to acclimate to new environments.
Avoid overexertion in hot and humid environments.
Wear proper clothing, including a hat.
Rest often, especially in extreme environments.
Do not allow outside pressure to push you beyond safe limits.
Make sure you are prepared when you head out in the heat and be safe.
I did this to share some information to the community as well as a way to refresh my brain on this subject. If you all like, I would be happy to share more on other topics that I will be reviewing such as Hypothermia, altitude illnesses, water purification, and other common expedition problems.
Sources:
Wildcare. Franklin R, Hubbell, DO
Emergency Care (12th addition)
And My own personal EMT, WEMT, And WFR notes.
*Disclaimer*
Before we go any further please know that I have done my best to provide the most accurate information available. Though I am a Nationally Certified WEMT, it is a hobby of mine and not a working career. Please use this article for information and awareness and seek professional medical help and advice when needed.
Causes:
Excessive dehydration from sweating and salt loss( without replacement) in a warm environment to the extent that the sweating mechanism can no longer function.
Environments with high humidity where sweat cannot evaporate off the skin( causing the cooling effect to be lost)
Exercising in a hot environment without taking precautions or recognizing early warning signs.
Contributing factors:
Age( the very young or very old are more susceptible)
Poor health
Use of certain medications
Prior history of heat illness
Heart disease
Fatigue
Alcohol consumption
Overexertion in a hot environment
Dehydration signs and symptoms
Headache and mild nausea
Irritability
Dark urine
Thirst
Dehydration treatment
1.Rehydrate with water and electrolytes by using a pre made solution like gatorade.
2.An improvised solution can be made by mixing 1tsp salt, 8tsps sugar and 1 liter of water.
3. Pre made oral rehydration solution(ORS)
4. Adding 1/2 a banana or 1/2 cup of orange juice to help supply potassium.
5.Maintaining hydration for the long term.
Heat Cramps signs and symptoms
Muscle pain and cramping, usually in the legs, caused by dehydration and electrolytes depletion.
Usually occurs after exercise.
Heat Cramps Treatment
Same as dehydration
Heat Exhaustion
Caused by working in a hot environment.
Is a combination of salt and water loss secondary to sweating in hot conditions.
Typically occurs in people who are not acclimatized to heat.
Those not use to working in a hot environment will lose salt more rapidly than someone whose physiology has adjusted to working in hot conditions.
Sodium plays an important role in maintaining cell wall integrity and membrane permeability, and is essential in maintaining normal homeostasis on a cellular level. If the amount if sodium in the extracellular fluid decreases, system wide cellular dysfunction will occur, causing flu-like or exhaustion symptoms.
Heat exhaustion is not a life threatening emergency: it is relived by rest, hydration, and electrolyte replacement.
Heat Exhaustion Signs and Symptoms
Fatigue
Thirst
Possible dizziness
Increased heart rate
Increased respiratory rate
Pale, clammy skin
Muscle cramps
Nausea without vomiting
Minor mood changes that can vary from a simple headache and slight anxiety to agitation and confusion.
Heat Exhaustion Treatment
Rest in a cool place
Find shade if possible
Remove excess clothing that may trap heat.
Apply cool cloths to body( e.g.damp bandanna).
Replace lost fluid and salt at least 1 -2 liters of oral rehydration solution.
Monitor body temperature
The patient should recover within 6-8 hours.
If the symptoms of heat exhaustion are ignored and the person continues to work and sweat hard, it can progress to heat stroke.
Heat stroke
Heat stroke is a life-threatening emergency.
If not treated immediately, it will quickly progress to coma and death.
The time from the onset symptoms to death can be as little as 15 minutes after the sweating mechanism fails and the core temperature begins to rise.
For those who survive, heat stroke can cause permanent disability.
Remember that heat stroke is always preventable. But it gets going, it is almost impossible to stop outside of an emergency department.
Heat stroke types
Classic
Dehydration in a hot environment caused by the person "over- sweating" without replacing lost fluids, which leads to the failure of the sweating mechanism, causing the core temperature to rise rapidly.
The patient is losing water faster than they are replacing it.
Once the sweating mechanism fails, cooling stops and the core temperature rises rapidly.
Exertional
Exercising in a hot and high humidity environment where the sweat mechanism cannot function because the sweat cannot evaporate; again, the core temperature rises rapidly. the sweat, even though copious, cannot evaporate fast enough, and the patient overheats.
Heat stroke pathology
Brain: encephalopathy ( swelling of the brain)
Liver: injury is common and the liver is most susceptible to early damage. Note: the liver is normally 2 degrees F warmer than the rest of the body so it has less of a temperature buffer and permanent damage is possible( and can occur faster).
Kidneys: renal failure is common.
Muscles: damage results from rhabdomyolysis( the rapid breakdown of skeletal muscle due to injury to the muscle tissue)
Blood: coagulopathy( clotting disorders) due to disseminated intravascular coagulation (DIC) is common.
Death occurs when the core temperature exceeds 107 degrees/41.6 degrees - the point at which the tissues of the brain are destroyed.
Heat stroke signs and symptoms
Patient will be red, hot, and mad due to vasodilation as the body tries to deal with the increase in core temperature.
The skin will be red, hot and dry( classic) or sweaty( exertional).
The patient cannot sweat because they are dehydrated or because evaporation is impossible(i.e. High humidity).
The patient will be disoriented, confused, combative, and may hallucinate wildly. These changes are caused by core temperatures above 104F/40C.
The patient may have seizures
The patient may not be able to urinate.
The patient will have increased heart and respiratory rate.
Heat stroke treatment
Heat stroke needs to be recognized early and treated aggressively. The duration and degree of temperature elevation determines the level of organ damage and the ability for the patient to recover.
1. Remove patient from heat and sun and place in a cool, shady place.
2. Remove clothing down to underwear.
3. Cool them immediately by soaking with cool water and fanning to accelerate evaporation.
4. Vigorously massage limbs to encourage hot blood to flow to extremities where it can cool.
5. Beware of shivering. Shivering produces heat. If the patient begins to shiver, stop cooling them until they stop shivering, then resume cooling at a less aggressive rate.
6. Hydrate once conscious.
7. Do not allow patient to exercise.
8. Evacuated immediately to definitive care ( do not let patient walk out on their own)
9. Continue cooling during transport.
Other treatments require a medical professional and will not be covered.
Prevention
Maintain adequate fluid and electrolyte intake.
Monitor the group for fluid and electrolyte intake.
Be aware of changing environmental conditions, allow time to acclimate to new environments.
Avoid overexertion in hot and humid environments.
Wear proper clothing, including a hat.
Rest often, especially in extreme environments.
Do not allow outside pressure to push you beyond safe limits.
Make sure you are prepared when you head out in the heat and be safe.
I did this to share some information to the community as well as a way to refresh my brain on this subject. If you all like, I would be happy to share more on other topics that I will be reviewing such as Hypothermia, altitude illnesses, water purification, and other common expedition problems.
Sources:
Wildcare. Franklin R, Hubbell, DO
Emergency Care (12th addition)
And My own personal EMT, WEMT, And WFR notes.
