GrumpyMedic Education

Real EMS. Real Critical Thinking.

GrumpyMedic Education Course

Hyperthermia

Recognition and prehospital management of environmental and exertional heat illness in adult and pediatric patients.

Adult & PediatricEnvironmental EmergencyHeat StrokeRapid Cooling

Start Course Take the Quiz Back to Courses

Section 01

Learning Objectives

By the end of this course, the learner should be able to:

Recognize the major types of heat-related illness.

Differentiate heat cramps, heat exhaustion, and heat stroke.

Identify altered mental status as a critical heat-stroke finding.

Apply rapid cooling strategies for severe hyperthermia.

Review adult and pediatric treatment considerations.

Make appropriate transport and destination decisions.

Section 02

What Is Hyperthermia?

Hyperthermia occurs when heat production or environmental heat exposure exceeds the body's ability to dissipate heat.

Normal Thermoregulation

The body normally controls temperature through sweating, vasodilation, convection, radiation, and evaporation.

High humidity, dehydration, heavy clothing, medication effects, illness, or extreme exertion can overwhelm these mechanisms.

Why It Becomes Dangerous

When thermoregulation fails, core temperature rises and cells begin to malfunction.

Continued heat exposure can lead to protein breakdown, inflammation, coagulopathy, brain injury, renal injury, liver failure, shock, and death.

Critical Principle

A patient with significant heat exposure and altered mental status should be treated as possible heat stroke even when a confirmed core temperature is not yet available.

Section 03

Types of Heat Illness

Heat illness exists on a spectrum. Rapidly recognize when a patient has progressed from a minor illness to heat stroke.

Mild Heat Illness

Heat Cramps

Painful muscle cramping associated with heat exposure, exertion, sweating, and electrolyte loss.

Common Findings

✓Painful muscle spasms
✓Heavy sweating
✓Normal or mildly elevated temperature
✓Normal mental status
✓Possible thirst and fatigue

Treatment Priorities

✓Move the patient to a cooler environment.
✓Stop exertion and allow the patient to rest.
✓Provide oral water or electrolyte solution when the patient is alert and can swallow safely.
✓Monitor for progression to heat exhaustion or heat stroke.

Moderate Heat Illness

Heat Exhaustion

Heat-related illness caused by fluid and electrolyte loss without the central nervous system dysfunction associated with heat stroke.

Common Findings

✓Weakness or fatigue
✓Dizziness or headache
✓Nausea or vomiting
✓Heavy sweating
✓Tachycardia
✓Possible hypotension
✓Usually normal mental status

Treatment Priorities

✓Move the patient to a cool environment.
✓Remove unnecessary clothing.
✓Begin active cooling.
✓Provide oral hydration when the patient is alert with a normal gag reflex.
✓Place the supine patient with legs elevated when appropriate.
✓Monitor closely for altered mental status or worsening instability.

Life-Threatening Emergency

Heat Stroke

Severe hyperthermia with central nervous system dysfunction caused by failure of normal thermoregulation.

Common Findings

✓Altered mental status
✓Confusion, agitation, seizures, or coma
✓Core temperature commonly 104°F (40°C) or greater
✓Hot skin that may be dry or sweaty
✓Tachycardia
✓Hypotension may develop
✓Rapid progression toward organ failure

Treatment Priorities

✓Begin rapid cooling immediately.
✓Do not delay cooling for IV access or transport preparation.
✓Use ice-water immersion when available and practical.
✓Continuously monitor airway, breathing, circulation, mental status, and temperature.
✓Prepare for seizures, vomiting, aspiration, dysrhythmias, and cardiovascular collapse.

Section 04

Recognizing Heat Stroke

Altered mental status is the key clinical feature separating heat stroke from less severe heat illness.

Core Temperature

Core temperature is commonly 104°F or greater, but treatment should not wait when the clinical presentation strongly suggests heat stroke.

CNS Dysfunction

Confusion, agitation, bizarre behavior, seizures, collapse, or coma are critical findings.

Rapid Progression

Cellular injury and organ dysfunction can develop quickly. Cooling is a time-sensitive intervention.

Heat Stroke Red Flags

Altered mental status

Seizure activity

Core temperature greater than or near 104°F

Hypotension

Signs of shock

Loss of airway protection

Severe agitation or coma

Dysrhythmia

Persistent vomiting

Evidence of organ dysfunction

Section 05

Risk Factors

Some patients are more likely to develop heat illness or deteriorate quickly.

Strenuous exertion or athletic activity

Outdoor labor in hot or humid conditions

Extremes of age

Dehydration

Poor access to air conditioning

Cardiovascular disease

Obesity

Recent illness

Alcohol or stimulant use

Medications such as diuretics or anticholinergics

Section 06

Patient Assessment

Perform routine patient care while rapidly identifying the severity of the heat emergency.

Primary Assessment

✓Assess airway protection.
✓Evaluate respiratory rate and effort.
✓Assess circulation and perfusion.
✓Determine level of consciousness.
✓Move the patient away from the heat source.
✓Remove unnecessary clothing and equipment.

Focused Assessment

✓Obtain vital signs and repeat frequently.
✓Obtain core temperature when appropriate equipment is available.
✓Ask about duration of exposure and exertion.
✓Determine fluid intake and urine output.
✓Review medications, illness, drugs, or alcohol.
✓Evaluate for trauma, infection, hypoglycemia, or toxicologic causes.

Do Not Rely on Skin Moisture

Heat-stroke patients do not always have dry skin. Exertional heat-stroke patients may continue sweating.

Section 07

Rapid Cooling

Rapid cooling is the most important treatment for suspected heat stroke.

Ice-Water Immersion

Preferred when severe exertional heat stroke is suspected and the method can be performed safely.

1Remove unnecessary clothing.
2Place the patient in an ice-water bath, tub, or tarp system.
3Keep the airway and upper chest accessible.
4Continuously monitor the patient.
5Massage the extremities when appropriate to encourage cooled blood return.

Tarp-Assisted Cooling

A tarp may be used as an improvised immersion container when a tub is unavailable.

1Place the patient in the center of the tarp.
2Raise the tarp edges to form a basin.
3Add water and ice.
4Maintain airway access and continuous monitoring.
5Assign personnel to stabilize the tarp and assist cooling.

Ice Packs and Evaporative Cooling

Use when immersion is unavailable, unsafe, or impractical.

1Apply ice packs to the groin and axillae.
2Consider additional packs around the neck when appropriate.
3Wet the skin with cool water.
4Use fans or moving air to improve evaporative cooling.
5Rotate packs and continue temperature reassessment.

Cooling Target

Continue active cooling while repeatedly reassessing temperature and clinical status. Avoid overcooling once the patient reaches approximately 102.2°F or 39°C, or follow the current applicable protocol and medical-control direction.

Section 08

Heat Exhaustion and Heat Cramps

Patients without central nervous system dysfunction may often be treated with cooling, rest, and hydration.

Oral Rehydration

Water or an electrolyte-containing fluid may be given when the patient is alert, has a normal gag reflex, and can swallow safely.

Avoid oral intake in patients with altered mental status, vomiting, aspiration risk, or anticipated procedures.

Positioning and Monitoring

A patient with heat exhaustion may be placed supine with legs elevated when clinically appropriate.

Continue monitoring for altered mental status, hypotension, worsening temperature, or progression to heat stroke.

Section 09

ALS Considerations

Advanced care supports circulation and treats complications but must not delay rapid cooling.

Adult Fluids

Consider an adult crystalloid bolus when clinically indicated and consistent with the current protocol.

Pediatric Fluids

Consider pediatric fluid administration by weight when indicated and consistent with the current protocol.

Cardiac Monitoring

Monitor for tachycardia, dysrhythmias, ischemia, electrolyte disturbance, and cardiovascular collapse.

Additional ALS Priorities

✓Establish vascular access without delaying cooling.
✓Check blood glucose.
✓Treat seizures according to protocol.
✓Manage airway failure or loss of airway protection.
✓Monitor ECG and perfusion.
✓Consider other causes of altered mental status.
✓Contact medical control when indicated.

Section 10

Transport Considerations

Cooling and transport must be coordinated rather than treated as competing priorities.

Cool First When Possible

When effective immersion cooling is available, continuing cooling on scene for a limited period may produce faster temperature reduction than immediate transport without effective cooling.

Assign adequate personnel and maintain continuous airway and cardiovascular monitoring.

Do Not Delay Necessary Transport

Begin transport when cooling cannot be performed effectively, the patient requires hospital intervention, the scene is unsafe, or the patient's condition requires immediate movement.

Continue cooling during transport whenever practical and safe.

Section 11

Clinical Scenario

Apply the course concepts to a patient encountered during an outdoor race.

Scenario

Runner Collapse

A runner collapses near the finish line during a summer road race. The patient is hot, confused, combative, and unable to answer questions appropriately. A core temperature of 104°F is obtained.

Assessment Findings

• Altered mental status
• Recent strenuous exertion
• Hot environment
• Core temperature of 104°F
• Tachycardia
• Severe heat-stroke concern

Immediate Priorities

• Remove the patient from the heat source.
• Remove unnecessary clothing.
• Begin immediate ice-water immersion or tarp cooling.
• Maintain airway access.
• Monitor temperature and vital signs.
• Prepare for seizure, vomiting, or deterioration.

Best Initial Action

Begin rapid cooling immediately while maintaining airway and cardiovascular monitoring. Do not delay cooling while waiting for IV access or transport preparation.

Section 12

Key Takeaways

Remember these principles when treating heat-related emergencies.

Altered mental status is the key indicator of heat stroke.

Rapid cooling is the most important early treatment.

Ice-water immersion is preferred for severe exertional heat stroke when practical.

Do not delay cooling for IV placement or transport preparation.

Heat-stroke patients may still be sweating.

Continue airway, cardiac, temperature, and mental-status monitoring throughout care.

Course Complete

Test Your Knowledge

Complete the 15-question Hyperthermia quiz to review recognition, cooling, fluid considerations, and transport priorities.

Start Hyperthermia Quiz Review Course

This educational material is intended for training and review. Always follow the most current statewide protocols, local service policies, medical-control direction, and your authorized scope of practice.