Heat Illness: Heat Cramps, Heat Exhaustion, Heat Stroke, and Cooling Practice Questions

25 multiple-choice questions on Heat illness: heat cramps, heat exhaustion, heat stroke, and cooling for paramedic and EMT students, from Chapter 39 (Environmental Emergencies). Read each question, pick your answer, then tap Show answer to check it and read the explanation.

25 practice questions

1. Heat cramps are painful muscle spasms caused mainly by:

   1. A. A core temperature above 40°C (104°F)
   2. B. Lactic acid from anaerobic exercise
   3. C. Loss of sodium and water in sweat
   4. D. Low calcium from poor dietary intake
   Show answer

   Answer: C. Loss of sodium and water in sweat

   Heavy sweating replaced with plain water leaves a sodium deficit that triggers cramps in heavily worked muscles. Core temperature is normal in heat cramps, which separates them from heat stroke.

2. A 35-year-old roofer has painful calf spasms after hours in the sun. He is alert with normal vital signs. The best care is to:

   1. A. Give salt tablets with a large glass of plain tap water
   2. B. Rest him in shade and give an oral electrolyte drink
   3. C. Start cold-water immersion before transport
   4. D. Massage the calves firmly until the spasm stops
   Show answer

   Answer: B. Rest him in shade and give an oral electrolyte drink

   Rest, cooling, gentle stretching, and an oral electrolyte solution relieve heat cramps. Salt tablets irritate the stomach and can cause hypernatremia, so they are not recommended.

3. A tourist faints after standing in a long line on a hot day. She recovers within a minute when supine. This is most consistent with:

   1. A. Heat syncope
   2. B. Heat stroke
   3. C. Heat cramps
   4. D. Hyponatremia
   Show answer

   Answer: A. Heat syncope

   Heat causes skin vasodilation and venous pooling, so standing still drops venous return and causes a brief faint. Heat stroke would cause persistent altered mental status with a high core temperature.

4. Heat exhaustion differs from heat stroke mainly because in heat exhaustion the patient has:

   1. A. Moist, sweaty skin
   2. B. A rapid heart rate
   3. C. Normal mental status
   4. D. Nausea and a headache
   Show answer

   Answer: C. Normal mental status

   Heat exhaustion causes fatigue, headache, nausea, tachycardia, and sweating with core temperature usually below 40°C (104°F) but no significant CNS dysfunction. Sweating can persist in heat stroke, especially the exertional type, so moist skin does not rule it out.

5. A 19-year-old soldier on a march is dizzy, nauseated, and sweating, with a pulse of 118/min, BP 104/68 mmHg, and a rectal temperature of 38.9°C (102°F). He is alert and oriented. You should:

   1. A. Let him rest in the shade, then rejoin the march
   2. B. Move him to shade, cool him, and give fluids
   3. C. Give acetaminophen to lower his temperature
   4. D. Give salt tablets with a liter of water
   Show answer

   Answer: B. Move him to shade, cool him, and give fluids

   Alert patients with heat exhaustion need removal from heat, rest, cooling, and oral or IV fluids. Antipyretics such as acetaminophen do not work in heat illness because the hypothalamic set point is not raised. He should not return to the march the same day, and salt tablets irritate the stomach and are not recommended; an oral electrolyte drink or IV fluid is used instead.

6. Heat stroke is defined by a core temperature generally above 40°C (104°F) together with:

   1. A. Central nervous system dysfunction
   2. B. Hot, dry, flushed skin with no sweating
   3. C. Severe dehydration and shock
   4. D. Widespread muscle cramping
   Show answer

   Answer: A. Central nervous system dysfunction

   The defining combination is hyperthermia with altered mental status, ataxia, seizures, or coma. Dry skin is common in classic heat stroke but often absent in exertional heat stroke, so it is not required.

7. Classic (nonexertional) heat stroke most often affects:

   1. A. Young athletes in early practice
   2. B. Soldiers on long training marches
   3. C. Laborers working in direct sun
   4. D. Older adults during a heat wave
   Show answer

   Answer: D. Older adults during a heat wave

   Classic heat stroke develops over days in people who cannot dissipate environmental heat, such as older adults, the chronically ill, and those on interfering medications. Athletes, soldiers, and laborers typically develop the exertional form.

8. A soldier collapses during a hard 10-km run on a mild 18°C (64°F) morning. He is confused, with a rectal temperature of 41°C (105.8°F). You should recognize that:

   1. A. Heat stroke cannot occur below 30°C (86°F)
   2. B. His confusion must be from low blood sugar
   3. C. The rectal reading is wrong in cool air
   4. D. Heat stroke can occur in mild weather
   Show answer

   Answer: D. Heat stroke can occur in mild weather

   In exertional heat stroke, intense muscle work generates heat faster than the body can lose it, so it can occur in cool or mild weather, especially with heavy clothing, poor fitness, or illness. Check glucose, but treat the high temperature with immediate cooling. A rectal temperature is the reliable measurement.

9. The most effective method of cooling a patient with exertional heat stroke is:

   1. A. Whole-body cold-water immersion
   2. B. Ice packs to the neck and groin
   3. C. A fan with cool water misting
   4. D. Cold IV fluids at a fast rate
   Show answer

   Answer: A. Whole-body cold-water immersion

   Immersing the trunk and limbs in cold or ice water cools at roughly 0.15°C/minute or faster, the highest rate of any field method. Ice packs to the neck, axillae, and groin cool much more slowly and are best used only when immersion is not possible.

10. A 17-year-old collapses at football practice. He is confused, and his rectal temperature is 41.2°C (106.2°F). The athletic trainer has an ice-water tub ready on the field, and the hospital is 15 minutes away. The best plan is to:

    1. A. Transport now and use ice packs en route
    2. B. Cool him in the tub, then transport him
    3. C. Start an IV and give cold saline first
    4. D. Give acetaminophen, then transport him
    Show answer

    Answer: B. Cool him in the tub, then transport him

    This is exertional heat stroke (core above 40°C with CNS dysfunction), and harm depends on how long the core stays dangerously hot. When cold-water immersion is ready on site, "cool first, transport second": whole-body immersion lowers core temperature at about 0.15 to 0.35°C per minute, far faster than anything possible in an ambulance, so he is cooled to the target with a rectal probe in place and then transported. Leaving now with ice packs to the neck, axillae, and groin cools several times more slowly and wastes the most important minutes. Cold IV saline helps only a little and should never delay immersion. Acetaminophen does not work in heat stroke because the hypothalamic set point is not raised, and it can add liver injury. (NATA 2015 position statement; ACSM 2023 consensus; WMS 2024 heat illness update.)

11. You are cooling a heat stroke patient in an ice-water tub. Cooling should stop when the rectal temperature reaches about:

    1. A. 36.5 to 37°C (97.7 to 98.6°F)
    2. B. 35 to 35.5°C (95 to 96°F)
    3. C. 38.5 to 39°C (101 to 102°F)
    4. D. 40 to 40.5°C (104 to 105°F)
    Show answer

    Answer: C. 38.5 to 39°C (101 to 102°F)

    Take the patient out of the tub at about 38.5 to 39°C (101 to 102°F). The core keeps falling for a while after removal, so stopping here prevents overshoot into hypothermia (the 2024 WMS update targets 38.3 to 38.8°C, the 2020 ILCOR/AHA first aid guidance cools until the core is below 39°C, and ACSM 2023 removes the patient at 38.6 to 39°C). Waiting for a normal 36.5 to 37°C in ice water overshoots. 35 to 35.5°C is hypothermia caused by the rescuer. At 40 to 40.5°C the patient is still at heat stroke temperatures, and organ injury continues. (WMS 2024 heat illness update; ACSM 2023 consensus; ILCOR 2020 first aid CoSTR.)

12. A 68-year-old man is found confused in a hot apartment with hot, dry skin and a temperature of 41°C (105.8°F). No tub is available. The best available field cooling is:

    1. A. Strip him, mist with water, and fan
    2. B. Cover him and give oral fluids
    3. C. Rub him down with isopropyl alcohol
    4. D. Give aspirin and cool his forehead
    Show answer

    Answer: A. Strip him, mist with water, and fan

    Evaporative cooling with water spray and moving air, plus ice packs to the groin, axillae, and neck, is the best alternative when immersion is impossible. Alcohol rubs are absorbed through dilated skin vessels, are flammable, and cool no better than water.

13. An older tourist who arrived in a hot climate 2 days ago has mild swelling of both ankles but no shortness of breath and normal vital signs. This most likely represents:

    1. A. Heat stroke
    2. B. Heart failure
    3. C. Heat edema
    4. D. Heat syncope
    Show answer

    Answer: C. Heat edema

    Heat edema is mild, self-limited swelling of the feet and ankles from vasodilation and fluid pooling during early heat exposure, especially in older adults. It is treated with elevation and support stockings, not diuretics. Absent dyspnea and normal vital signs argue against heart failure, and there is no collapse or confusion.

14. A heat stroke patient being cooled begins to shiver vigorously. Per protocol, you may treat this with:

    1. A. An antipyretic
    2. B. A benzodiazepine
    3. C. An antihistamine
    4. D. A beta-blocker
    Show answer

    Answer: B. A benzodiazepine

    Shivering generates heat and slows cooling, so a small dose of a benzodiazepine such as midazolam is used to suppress it and to control seizures. Antihistamines have anticholinergic effects that further impair sweating.

15. A construction worker has a fine, itchy red rash of tiny bumps on his neck and chest where his clothes were tight and sweaty. This is most likely:

    1. A. Heat stroke
    2. B. Meningococcemia
    3. C. Contact frostbite
    4. D. Heat rash
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    Answer: D. Heat rash

    Heat rash forms when sweat ducts become blocked in hot, humid conditions, producing small red, itchy bumps in covered or tight areas. It is treated by cooling and keeping the skin dry. It does not cause fever or confusion, unlike heat stroke or meningococcemia, and frostbite is a cold injury.

16. Complications of heat stroke include all of the following organ problems EXCEPT:

    1. A. Acute kidney injury
    2. B. Polycythemia
    3. C. Liver failure
    4. D. Disseminated intravascular coagulation
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    Answer: B. Polycythemia

    Heat stroke causes multiorgan injury including AKI, hepatic necrosis, DIC, ARDS, and cerebral edema. Polycythemia, an increase in red cell mass, is not a complication of heat stroke.

17. At a marathon medical tent, a runner with suspected exertional heat stroke needs cooling, but no tub is available. You have a tarp, ice, and water. The most effective option is to:

    1. A. Wrap him in a tarp filled with ice water
    2. B. Place ice packs at the neck and groin
    3. C. Mist him with water and fan him
    4. D. Run cold IV saline wide open through two lines
    Show answer

    Answer: A. Wrap him in a tarp filled with ice water

    Tarp-assisted cooling with oscillation (the "taco") holds the patient in a tarp filled with ice water while rescuers rock it, so most of the body is in contact with circulating cold water. It cools at close to the rate of a tub, and the WMS 2024 and ACSM 2023 guidance list it as the best option when a tub is not available. Ice packs at the neck, axillae, and groin cover little skin and cool several times more slowly. Misting and fanning are slower again in an exertional patient and work poorly in humid air, though they are a reasonable choice for classic heat stroke when nothing better is available. Cold IV fluid lowers core temperature only slightly and is an add-on, never a substitute for whole-body cooling. (WMS 2024 heat illness update; ACSM 2023 consensus; Luhring 2016.)

18. A 45-year-old man with heat stroke is being cooled. His BP is 84/50 mmHg. A reasonable fluid approach is:

    1. A. Hypotonic fluids to replace the free water lost
    2. B. Withholding fluids until he is cooled
    3. C. Large volumes of dextrose 5% in water
    4. D. Isotonic boluses with frequent reassessment
    Show answer

    Answer: D. Isotonic boluses with frequent reassessment

    Many heat stroke patients are volume depleted, and hypotension often improves as cooling reverses vasodilation, so give normal saline in boluses and reassess lung sounds. Hypotonic fluids such as D5W can worsen cerebral edema and hyponatremia.

19. The 2020 AHA first aid guidance for exertional heat stroke recommends immersing the patient in water at:

    1. A. 30 to 35°C (86 to 95°F)
    2. B. 37 to 40°C (98.6 to 104°F)
    3. C. 1 to 26°C (34 to 79°F)
    4. D. Above 40°C (104°F)
    Show answer

    Answer: C. 1 to 26°C (34 to 79°F)

    Whole-body immersion in cold water, from ice water up to about 26°C (79°F), is recommended until core temperature falls below 39°C (102.2°F). Water warmer than this cools too slowly to prevent organ damage.

20. On a hot day, an 80-year-old is found confused with a temperature of 40.3°C (104.5°F) and a cough. You cannot tell whether this is heat stroke or sepsis. You should:

    1. A. Give only antipyretics and wait to cool her
    2. B. Cool her and also treat for possible sepsis
    3. C. Withhold cooling until infection is excluded
    4. D. Cool her only after a blood culture is drawn
    Show answer

    Answer: B. Cool her and also treat for possible sepsis

    Heat stroke and severe infection can look alike in older adults, and both can coexist. Begin active cooling, which is harmless if she is septic, while supporting perfusion and reporting the possible infection so cultures and antibiotics are started. Waiting delays care, and antipyretics do not work in heat stroke.

21. During a heat wave, a young adult who used methamphetamine is agitated with a temperature of 41.7°C (107°F). The priority is to:

    1. A. Restrain him prone and wait for police
    2. B. Give acetaminophen and oral fluids
    3. C. Transport first, then start cooling
    4. D. Sedate him and begin rapid cooling
    Show answer

    Answer: D. Sedate him and begin rapid cooling

    Stimulants increase heat production and agitation adds more, so sedation with a benzodiazepine plus aggressive cooling treats both. Prone restraint risks asphyxia and does nothing to lower temperature.

22. A patient with suspected heat stroke has a rectal temperature of 39.4°C (103°F) but is confused and ataxic after a long run. You should:

    1. A. Rule out heat stroke by the reading
    2. B. Wait for a second reading in an hour
    3. C. Treat as heat stroke and cool
    4. D. Treat as heat cramps and give salt
    Show answer

    Answer: C. Treat as heat stroke and cool

    Cooling may begin before measurement and temperature falls quickly, so a reading below 40°C (104°F) does not exclude heat stroke when CNS dysfunction is present. Waiting delays the one treatment that saves lives.

23. Heat exhaustion patients with nausea and vomiting who cannot take oral fluids should receive:

    1. A. IV normal saline
    2. B. Oral salt tablets
    3. C. IV dextrose 50%
    4. D. Nothing until cool
    Show answer

    Answer: A. IV normal saline

    An IV of isotonic saline replaces volume and sodium when vomiting prevents oral rehydration. Salt tablets would likely be vomited and irritate the stomach.

24. Which finding most clearly separates exertional heat stroke from heat exhaustion?

    1. A. Confusion or seizures
    2. B. Profuse, drenching sweating
    3. C. Rapid pulse
    4. D. Muscle cramps
    Show answer

    Answer: A. Confusion or seizures

    Any CNS dysfunction in a hyperthermic patient signals heat stroke and demands immediate cooling. Sweating and tachycardia occur in both conditions.

25. A long-distance runner collapses. Glucose is normal. She has had a seizure and has a rectal temperature of 37.4°C (99.3°F) after drinking large volumes of water. The most appropriate treatment, where protocol allows, is:

    1. A. Ice-water immersion
    2. B. Hypertonic saline
    3. C. Large normal saline boluses
    4. D. Oral sports drink
    Show answer

    Answer: B. Hypertonic saline

    A seizure after overdrinking during a long event, with a normal temperature and glucose, points to severe exercise-associated hyponatremia with cerebral edema. The WMS 2019 update recommends a 100 mL bolus of 3% saline, repeated up to twice more at 10-minute intervals until neurologic symptoms improve; when sodium cannot be measured and the picture fits, it may be given empirically. Ice-water immersion treats heat stroke, and she is not hyperthermic. Large normal saline boluses barely raise the sodium and add volume to a patient who is already fluid-overloaded. Sports drinks are hypotonic and would add more free water, and she cannot safely drink after a seizure. (WMS 2019 EAH update.)