Scene Assessment

The riskiest time for the EMT is arrival at the scene. The EMT must rapidly assess any risks that may be present and must quickly make appropriate decisions and take actions to ensure that neither the patient nor the EMTs become exposed to increased risk. 

En Route

   Emergency medical dispatch (EMD) is designed to assure the EMT receives appropriate information to be prepared to manage the scene appropriately. Good EMD includes:

  • pertinent weather information.
  • traffic delays.
  • other delays such as raised bridges or blocked railway crossings.
  • fastest, safest route to follow.
  • identified alternative routes.
  • prearrival instructions regarding care for the patient.

Essential dispatch information includes as full and complete a description of the scene as possible. Dispatch information enables the EMT to determine whether the call:

  • is a trauma or medical call.
  • includes any life-threatening conditions.
  • involves fire or building hazards.
  • involves other hazards such as downed power lines, broken gas lines, spills, or vicious animals.
  • requires special rescue equipment.
  • involves multiple vehicles or otherwise indicates that more medical personnel may be needed on the scene.
  • involves the possibility of helicopter evacuation.
  • requires special personnel and equipment. Waiting to request special services may prevent necessary patient care. It can be canceled once the EMT is on the scene.
  • will be affected by weather conditions.
  • involves very hot or cold climates which may aggravate the patient's condition.
  • involves any type of reported violence. EMTs should never enter the scene until law enforcement officers have secured the scene.
  • includes prearrival instructions that have been given to the caller to provide care to the patient until EMS arrives.

The first two elements of a dispatch, location and type of call, help to determine if an immediate need for additional or specialized resources exists. Calls that involve respiratory, cardiac, or motor vehicle collisions often require additional personnel, who should be dispatched immediately.

Most larger urban fire departments have specialized hazardous materials units and specially trained personnel to handle these types of calls. A good EMD center must have all the necessary resources available for immediate contact once the determination is made that a hazardous materials incident has occurred.

Scene Size-Up

 The EMT should avoid the natural urge to rush into a scene and immediately begin providing patient care. This leads to "tunnel vision" and may lead the EMT to overlook safety precautions and the need for additional assistance. Important points to remember in scene size-up include:

  • Scene safety issues.
  • Use of body substance isolation precautions.
  • Mechanism of injury.
  • Nature of illness.
  • Number of patients.
  • Need for additional help.
  • Triage.

At the Scene

The EMT should determine that the scene is secure and safe to enter as they approach the scene. The EMT should determine if scene hazards still exist (e.g., downed power lines, unstable building structures, armed perpetrators, etc.). In the case of an assault, the EMT should know where the weapon is.

Establish a Danger Zone:

  • With no apparent hazards, the danger zone extendsat least 50' in all directions from wreckage.
  • With spilled fuel, the danger zone extends a minimum of 100' in all directions from the wreckage. (Park upwind if possible.)
  • When a collision vehicle is on fire, the danger zone is at least 100' in all directions even if the fire is small. 
  • When wires are down, the danger zone is at least one full span of wires from the poles to which broken wires are attached.
  • When a hazardous material is involved, check the North American Emergency Response Guidebook published by the U.S.D.O.T., Transport Canada, and the Secretariat of of Communications and Transportation of Mexico or contact the agency CHEMTREC (Chemical Transportation Emergency Center, Washington, D.C. 24-hour hotline at 1-800-424-9300. 

Warning Signs of Crime Scenes and Violence:

  • fighting or loud voices.
  • weapons used or visible.
  • signs of alcohol or other drug use.
  • unusual silence.
  • knowledge of prior violence.

The EMT must quickly evaluate the total scene of a trauma. For instance, this evaluation involves determining how the vehicle(s) collided, the speed involved at time of impact, and whether safety belts or air bags restrained the victim. In other cases, it is important to know the amount of debris that fell on the victim, what type of machinery was involved in the accident, etc. Evaluation is very important because it serves to guide the EMT during the physical examination of the patient in looking for and identifying possible injuries.


Immediately on entering the scene, the EMT should establish control. Chaos is common at an emergency scene and family, patients, and bystanders may be frightened or anxious. In a crime scene, the EMT must be aware that the crime scene must be preserved. If there is a physician present at the scene, the EMT should try to put the physician in contact with the emergency physician. The physician should accompany the EMTs to the hospital if the physician has initiated treatment and expects the EMT to continue care or if the level of care is beyond that of current licensure/ certification of the EMT. 

The key element in gaining control of a scene is the confidence with which the EMT interacts with the patient(s) and also with support personnel, family members, and other medical personnel on the scene. IF a physician is on the scene, ask rather than direct if you see something that should be done. Care of the patient must be the directing factor. The EMT will realize better results in patient care by demonstrating respect.

Many people do not like strangers calling them by their first name, so be polite and ask first. An example of an introduction is "Hello, my name is ______, and I'm an Emergency Medical Technician. I'm trained to assist you and am here to help you. Can you tell me what your problem is today?"


The EMT who feels and exhibits confidence must also demonstrate competence and compassion for their co-workers and other medical personnel, as well as for the patient and family. Competence is best demonstrated by directing and initiating care in a smooth and direct manner that tells both your co-workers and the patient that you know what you are doing and how to do it. Compassion for the patient and his or her familyis demonstrated by actions and words. Remember, there are times when compassion must come after life-saving techniques, and never let compassion interfere with personal safety.

Other Considerations

Personal protective equipment should always be worn when there is risk of contamination by blood, airborne contaminants, or other potentially infectious materials. Any EMT involved in extrication should always be in full protective clothing as indicated by the conditions at the scene. 

A mass casualty incident (MCI) is extremely important that the EMT recognize (even before leaving the unit) that if additional personnel and equipment are needed they must be summoned early. One good definition of an MCI is any scene that the initial responding unit cannot handle alone. Triage is the sorting and allocation of treatment to patients to maximize the number of survivors. Stopping to assess and treat the first patient prevents the assessment of other patients and delays the calling of additional resources and the performance of life-saving interventions.  The EMT must know how and what agencies to contact for appropriate back-up units in the community. Know your resources.

Bio-Ethical Considerations

Primum no nocere is Latin for "first do no harm." It is the first tenet of patient care. One problem that the EMT has always had to face is the question of whether resuscitation is appropriate to begin or to continue once started. Certain trauma patients cannot be saved no matter what level of care is immediately available to them.

DNR orders (and durable power of attorney, advanced directives, and living wills) are traditionally associated with hospital and long-term care facilities and may not have any relevance to EMS. RNI (resuscitation not indicated) or EMS do not resuscitate legislation is designed to give patients the opportunity to express their wishes, in writing, concerning resuscitation efforts and to give prehospital care providers the legal support to follow these decisions. Decisions to not resuscitate, made in direct contact with a physician, require a rapid evaluation and description of the scene and the patient(s). EMS DNR orders do not preclude the administration of procedures intended for the comfort of the patient (eg., oxygen, suctioning, administration of analgesics, controlling bleeding, and making the patient comfortable).

The proper procedure for the EMT to follow if he or she encounters an EMS DNR order is:

  1. Perform initial assessment.
  2. Verify identification of patient by license or other signed photo identification or family member or other party who can positively identify the patient.
  3. Administer oxygen by mask or cannula.
  4. Suction the airway.
  5. Manage airway with basic procedures (no intubation or other advanced procedures).
  6. Control bleeding.
  7. Administer analgesics (EMT-P level only).
  8. Make the patient comfortable.
  9. Support family members and make them comfortable.


If possible, contact medical direction for consultation is there are any question about the validity of an EMS DNR order or if there is evidence of an attempted homicide. In such cases, initiate resuscitation until questions have been answered. Patients may wear a special identification bracelet indicating an EMS DNR order.

A durable power of attorney may give a person the power to make decisions on behalf of the person who authorizes it. In such cases, the EMT should follow the basic procedure above and, in addition, should determine that the bracelet or document is original and not defaced in any way. If defacement is found, resuscitation must be initiated. Ask family members to search for the documents or bracelet but, if they cannot find them immediately, initiate resuscitation and contact medical direction. 

Review Questions:

1. Identify the elements that are considered part of the scene survey.

2. What type of call, medical or trauma, can present the greatest number of risks to the EMT and why?

3. What are the benefits of evaluating the mechanism of injury at a scene to the EMT?

4. What are the two main reasons for EMTs to review the dispatch information while en route to a call and perform a quick yet thorough scene survey on arrival.

5. For each of the following dangers, describe the actions that must be taken to remain safe at a collision scene.

  • leaking gasoline
  • toxic or hazardous material spill
  • vehicle on fire
  • downed power lines

6. List several indicators of violence or potential violence at an emergency scene.

7. List several medical and trauma situations which you may require additional assistance.

8. Describe common mechanisms of injury patterns.

9. List sources of information about the nature of a patient's illness.

10. Describe several situations where it is appropriate to wear disposable gloves. Describe situations where you would additionally wear protective eyewear and mask. Describe situations where you would wear an N95 or HEPA respirator.