The first step in the process of effectively handling an emergency is notification that an emergency situation exists. This information can come from one or more of three primary sources: alarm systems, verbally from other occupants, or from an individual’s senses. Automatic alarm systems provide the most rapid notification, allowing maximum escape time. Manual alarm systems help speed the notification of other
occupants once someone in the structure becomes aware of the emergency. The advantage of a manual alarm is the ability to rapidly notify all occupants in all areas of the building that an emergency exists. The major disadvantages of the manual alarm are:
- An individual must discover the emergency first, which delays warning to other occupants.
- The manual nature of the system means that an individual must take action to activate the alarm.
- If the person who discovers the emergency does not think of the alarm or decides that the emergency is not significant enough to activate the alarm, another delay occurs.
Verbal notification of emergencies from one occupant to the next is acceptable only in limited circumstances. Small facilities with only a few employees may be able to make this work effectively. If a shout of “Fire!” cannot be heard throughout the entire facility, this method will not be effective. Detection of emergencies with human senses is the least desirable option. The abilities of occupants to sense the
presence of an emergency are considerably slower and more limited than an alarm system’s capabilities.
Once notification of an emergency situation has been made by any of the methods just described, the individual must recognize the need for action. This depends mostly on how great the individual perceives the threat to be. If the first impression of the fire alarm signal is “Oh, great, another false alarm,” the actions taken by the individual will be slow and not very effective. The opposite end of the perception scale is an “I’m going to die” reaction, which will not bring about the most effective action either. The latter reaction can lead to irrational behavior and taking action without thinking about the consequences. Ideally, occupants will recognize that a real threat is present but will remain calm enough to think through the actions necessary to escape safely. After an individual has been notified of an existing emergency, he/she must evaluate potential courses of action. The initial decision can be divided into three categories of action:
(1). The person can stay where he/she is and wait for help. (2). He/she can exit in a number of directions.
(3). The occupant can attempt to control the emergency.
Before the person can select a course of action, he/she must have examined the available options. This is one of the key areas which requires training. To evaluate emergency situations effectively, occupants need information about the impact different circumstances will have on their ability to escape. Normally, an individual on an upper floor of a building would use the elevator to go to the ground floor. During a fire, this could be a disastrous choice. Without the knowledge that this potential escape route carries great risk, the person cannot evaluate it properly. Once the choices have been evaluated, the individual must select the most appropriate course of action. As soon as the decision to wait, escape, or try to control the emergency has been made, the occupant must identify choices available to him/her in the category that has been selected. If an escape is to be attempted, he/she must identify the accessible escape routes. Several will usually exist, but not all of them will provide a safe means of escape. Once the options have been analyzed, the individual must select the one that offers the greatest chance of successful escape. To make a successful escape, he/she must identify and reach an exit access, travel through the exit access to the
exit, leave the structure via the exit, and take appropriate action once outside the structure.
If the individual decides that the most effective strategy is to wait for help to arrive, he/she must secure the waiting area to the greatest extent possible. This means limiting the potential for the entrance of smoke, fire gases, and heat. The occupant must confirm that someone in a position to help knows that he/she is waiting for help, the exact location, and the current conditions. If he/she decides to attempt to control the emergency, several items must be evaluated. The fire must be small enough to be easily extinguished. The individual must have access to a means of control, such as a fire extinguisher, and the skills to use it. He/she must consider whether an attempt to control the fire will eliminate other lifesaving options. For example, if the fire is close to the only exit from the area, any attempt to control the fire may allow it to grow enough to block the exit. Smoke and fire gases can also become life threatening in a short time. If all of these decisions have been made carefully, the occupant should be able to select those actions which provide the greatest chance for survival.
You can rad the Full text body from : Schroll R.C. , Industrial Fire Protection Handbook, 2ndEd 
