Utility and Fire Hazards, and Prolonged Entrapment Practice Questions

25 multiple-choice questions on Utility and fire hazards, and prolonged entrapment for paramedic and EMT students, from Chapter 49 (Vehicle Extrication and Special Rescue). Read each question, pick your answer, then tap Show answer to check it and read the explanation.

25 practice questions

1. A live power line is lying on the ground, and voltage spreads out from it in rings. To leave the area safely, you should:

   1. A. Run away from it with long strides
   2. B. Walk away on your heels in big steps
   3. C. Crawl away on your hands and knees
   4. D. Shuffle away with your feet together
   Show answer

   Answer: D. Shuffle away with your feet together

   Voltage falls off in rings from where the line touches the ground, so a long stride puts the feet at different voltages and current flows through the legs (step potential). Shuffling with the feet together keeps them at nearly the same voltage; crawling puts hands and knees at different points.

2. At a house fire at midday, the utility has shut off grid power, but the roof has solar panels. You should assume that the panels and their wiring:

   1. A. Are safe now that grid power is turned off
   2. B. Carry voltage at night when lights are switched on
   3. C. Are still energized while light reaches them
   4. D. Go dead once the inverter is unplugged from the wall
   Show answer

   Answer: C. Are still energized while light reaches them

   Solar panels generate electricity whenever light falls on them, so the panels and the wiring between them and the inverter can stay energized even after the utility cuts grid power. Responders should avoid cutting into or touching panels and conduits until the system is confirmed safe.

3. A power line lies across a car, and the car is now catching fire. The driver must get out. You should tell him to:

   1. A. Climb out and walk away holding the door
   2. B. Stay inside the car until the fire has been put out
   3. C. Step out one foot at a time and then run
   4. D. Jump clear with feet together and shuffle away
   Show answer

   Answer: D. Jump clear with feet together and shuffle away

   If he must leave an energized car, he jumps so that no part of his body touches the car and the ground at the same time, lands with feet together, and shuffles away. Holding the door while stepping down makes him the path to ground.

4. A downed power line has stopped sparking. It should still be treated as live because:

   1. A. The wire stores charge like a battery
   2. B. Automatic reclosers may re-energize it
   3. C. Lines spark when a person comes near
   4. D. The pole transformer stays on until dark
   Show answer

   Answer: B. Automatic reclosers may re-energize it

   Utility systems have reclosers that try to restore power several times after a fault, so a quiet line can suddenly become energized again. Only the utility can confirm that a line is dead.

5. Rescuers should not try to move a downed line with a dry wooden pole or rope because:

   1. A. These items can conduct high voltage
   2. B. They are too heavy to hold steady
   3. C. They can damage the line's covering
   4. D. The wire may slide off and roll away
   Show answer

   Answer: A. These items can conduct high voltage

   At distribution and transmission voltages, wood, rope, and other items that seem to insulate can conduct, especially if damp or dirty. Lines are moved only by the utility with rated tools.

6. A downed line rests on a long wire fence. You should treat the fence as:

   1. A. Safe beyond 3 m (10 ft) from the line
   2. B. Safe if it is made of galvanized wire
   3. C. Energized along its whole length
   4. D. Energized just at the point of contact
   Show answer

   Answer: C. Energized along its whole length

   Metal fences, guardrails, and wet ground can carry current far from where a line touches them. Treating only the contact point as dangerous puts rescuers at risk.

7. A lineworker is unconscious in a bucket truck next to energized lines. Rescue should be done by:

   1. A. EMS crews using the truck's lower ground controls
   2. B. Bystanders who lower the bucket by hand
   3. C. The first firefighter to reach the truck
   4. D. Trained utility crews after power is controlled
   Show answer

   Answer: D. Trained utility crews after power is controlled

   The bucket and truck may be energized, and lowering it near live lines takes training and the utility's control of power. EMS waits outside the hazard area to treat him once he is brought down.

8. A backhoe has struck a buried natural gas line at a trench site, and you smell gas. You should:

   1. A. Have the operator stop the gas with dirt
   2. B. Move upwind and keep ignition sources away
   3. C. Shut off the ambulance in the gas cloud
   4. D. Use a flashlight to find the leaking pipe quickly
   Show answer

   Answer: B. Move upwind and keep ignition sources away

   Escaping natural gas can ignite from a spark, so crews move away and upwind, keep vehicles and radios away from the cloud, and wait for the utility to shut off the supply. Approaching to look for the leak puts rescuers in the cloud.

9. When approaching a burning car, rescuers should come from:

   1. A. Upwind and uphill, at an angle to the car
   2. B. Downwind, so the smoke shields them
   3. C. Straight at the front bumper of the car
   4. D. Downhill, where the fuel will be easy to see
   Show answer

   Answer: A. Upwind and uphill, at an angle to the car

   Approaching from upwind and uphill keeps rescuers out of toxic smoke and away from burning fuel that runs downhill. An angled approach avoids the front and rear bumpers.

10. Rescuers avoid the front and rear of a burning car mainly because:

    1. A. The airbags fire out through the bumpers
    2. B. The fuel tank is mounted in the front
    3. C. The lights can shatter and cut rescuers
    4. D. Heated bumper and hood struts can burst
    Show answer

    Answer: D. Heated bumper and hood struts can burst

    Energy-absorbing bumpers and gas-filled hood and hatch struts can burst when heated and fly off with great force. Approaching from the sides at an angle keeps rescuers out of their path.

11. A small fuel fire starts under a crashed car. The fire extinguisher class designed for flammable liquids is:

    1. A. Class B
    2. B. Class A
    3. C. Class C
    4. D. Class D
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    Answer: A. Class B

    Class B fires involve flammable liquids such as gasoline. Class A is ordinary combustibles, Class C is energized electrical equipment, and Class D is combustible metals such as magnesium.

12. Firefighters spray a small amount of water on a burning magnesium wheel. This can:

    1. A. Put the fire out within a few seconds
    2. B. Cause a violent flare-up of the fire
    3. C. Make the wheel safe to touch quickly
    4. D. Turn the metal into a harmless powder
    Show answer

    Answer: B. Cause a violent flare-up of the fire

    Burning magnesium reacts with small amounts of water and can flare violently; it needs a Class D agent or very large volumes of water. Expecting a little water to put it out is the common error.

13. An electric car was pulled from salt water after a flood. It should be:

    1. A. Driven to a dealer for battery service
    2. B. Hosed off and then parked in a garage
    3. C. Kept away from buildings; it may ignite later
    4. D. Charged right away to help dry out the battery
    Show answer

    Answer: C. Kept away from buildings; it may ignite later

    Salt water can short-circuit a lithium-ion battery and start a fire hours or days later, so flooded electric vehicles are kept outside and away from structures. Charging or garaging it raises the fire risk.

14. A rescuer runs his gloved hand along a hydraulic tool hose to find a leak. This is unsafe because:

    1. A. The hose is too hot to touch during use
    2. B. A pinhole jet can inject fluid under the skin
    3. C. The glove will stick to the hydraulic fluid
    4. D. His hand will block the tool's pressure gauge
    Show answer

    Answer: B. A pinhole jet can inject fluid under the skin

    Fluid escaping from a pinhole at high pressure can pierce gloves and skin and inject oil deep into tissue. Leaks are found with cardboard or by looking, never with a hand.

15. A driver has been trapped for 45 minutes on a rainy 10°C (50°F) night. Besides his injuries, a major concern is:

    1. A. Hypothermia, which can worsen his bleeding
    2. B. Trench foot developing from his wet shoes and socks
    3. C. Hypertension from cold vessel spasm
    4. D. Dehydration from rapid breathing
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    Answer: A. Hypothermia, which can worsen his bleeding

    Wet, still, injured patients lose heat quickly even in mild weather, and hypothermia impairs clotting and worsens bleeding in trauma. Trench foot takes many hours to days of wet cold, and cold-induced vessel narrowing is not the main threat; heat loss is. Fluid lost through rapid breathing is minor over 45 minutes.

16. To limit heat loss in a patient trapped outdoors in cold, windy weather, the best measure is to:

    1. A. Rub his arms and legs briskly to warm him up
    2. B. Remove his clothing to check for injuries
    3. C. Give him warm coffee by mouth to drink
    4. D. Cover him and shield him from wind and wet
    Show answer

    Answer: D. Cover him and shield him from wind and wet

    Blankets, a tarp, and wind and rain shields reduce heat loss by convection, conduction, and evaporation. Clothing is cut away only as needed and replaced with cover, and patients who may need surgery are not given food or drink.

17. In a cold, trapped patient, a pulse oximeter on the finger may give poor readings because of:

    1. A. The noise of the rescue tools
    2. B. Carbon monoxide from the cold
    3. C. Poor blood flow to cold fingers
    4. D. Bright scene lighting in the car
    Show answer

    Answer: C. Poor blood flow to cold fingers

    Cold causes vasoconstriction in the fingers, so the oximeter may not detect a pulse or may read low. An earlobe or forehead sensor or warming the hand can help.

18. A trapped patient's blood pressure is 88/56 mmHg, and he has severe pain from a pinned leg. Rescuers ask for your input before they move the leg. The best response is to:

    1. A. Have them move the leg before any treatment
    2. B. Refuse analgesia until his pressure is normal
    3. C. Ask for a short delay to give analgesia first
    4. D. Stop the rescue until he reaches the hospital
    Show answer

    Answer: C. Ask for a short delay to give analgesia first

    Coordinating with the rescue team allows pain control before the most painful step, choosing an agent and dose that are safe at his blood pressure. Moving the leg first causes needless suffering, and analgesia should not be withheld only because of borderline pressure.

19. A worker has been trapped for 4 hours with his legs crushed under a machine. After release, he is best taken to a hospital that can provide:

    1. A. Hyperbaric oxygen chamber treatment
    2. B. Burn care and skin grafting
    3. C. Pediatric intensive care
    4. D. Hemodialysis and trauma surgery
    Show answer

    Answer: D. Hemodialysis and trauma surgery

    Crush syndrome releases potassium, myoglobin, and acid that can cause kidney failure and dangerous rhythms, so a trauma center with dialysis is the right destination. Hyperbaric oxygen is not the first need.

20. Field amputation to free a trapped patient is considered:

    1. A. Only when life is at risk and no other option works
    2. B. Whenever the extrication will take over 30 minutes
    3. C. For any limb that is badly mangled or crushed
    4. D. When the patient asks to be freed more quickly
    Show answer

    Answer: A. Only when life is at risk and no other option works

    Field amputation is a last resort for a patient whose life is threatened and who cannot be freed any other way, such as with a rising structure or fire hazard. Long extrication or a mangled limb alone does not justify it.

21. When field amputation is needed to free a trapped patient, it is usually done by:

    1. A. The senior paramedic on scene using a rescue saw
    2. B. A physician or surgical team sent to the scene
    3. C. The rescue officer with a hydraulic cutter
    4. D. A flight nurse with standing protocols
    Show answer

    Answer: B. A physician or surgical team sent to the scene

    Most systems send a physician or surgical team to perform field amputation, with sedation and analgesia, because of its risks and its permanent result. Paramedics and rescue crews prepare the patient and scene.

22. A 60-year-old woman has been trapped for 2 hours and is terrified. She asks if she is going to die. The best response is to:

    1. A. Tell her that everything will surely be fine
    2. B. Stay with her, keep talking, and be honest
    3. C. Change the subject and talk about the weather
    4. D. Leave her so the rescuers can work faster
    Show answer

    Answer: B. Stay with her, keep talking, and be honest

    Honest, calm reassurance and steady contact help a trapped patient cope and let you follow her mental status. False promises damage trust if the situation worsens.

23. A patient trapped under collapse debris for hours is coughing from dust. You can protect his airway by:

    1. A. Placing a nasal airway in each of his nostrils
    2. B. Spraying water directly into his mouth and nose
    3. C. Having him hold his breath while crews are cutting
    4. D. Giving him a mask or cloth over his nose and mouth
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    Answer: D. Giving him a mask or cloth over his nose and mouth

    A dust mask, or cloth if none is available, filters debris during cutting and breaking. A nasal airway does not filter dust, and spraying water into the mouth risks aspiration.

24. A driver is trapped in a car parked in full sun on a 35°C (95°F) day. Extrication will take 30 minutes. A concern for him is:

    1. A. Heat illness; shade and cool him as able
    2. B. Sunburn on his exposed arms and face
    3. C. Contact burns from the hot steering wheel
    4. D. Carbon monoxide from the hot engine
    Show answer

    Answer: A. Heat illness; shade and cool him as able

    A car in the sun becomes very hot inside, and trapped patients cannot escape it; shading the car with a tarp and cooling the patient reduce heat illness. Sunburn and contact burns are lesser problems next to a rising core temperature, and a stopped engine is not a carbon monoxide source. Rescuers working in turnout gear need rest and hydration for the same reason.

25. Rescuers at a crashed late-model electric SUV are unsure where its high-voltage parts and safe cutting zones are. The most reliable source is:

    1. A. The owner's manual found in the glove box
    2. B. A general diagram of how most EVs are built
    3. C. The maker's rescue sheet for that exact model
    4. D. The tow truck operator who will remove the car
    Show answer

    Answer: C. The maker's rescue sheet for that exact model

    Manufacturers publish emergency response guides and one-page rescue sheets (in a standard ISO 17840 layout) that show each model's high-voltage battery and cables, areas not to cut, airbag inflators, reinforced pillars, and shutdown steps. They are reached by app, by a QR code on the car, or online, and NFPA's EV field guide says the maker's guide takes precedence over general guidance. An owner's manual is not written for rescuers and may be inside a crushed car. A general diagram cannot show where a specific model places its battery and cables, which differs between models. A tow operator knows how to move the vehicle but is not the authority on its rescue hazards.