After a critical incident, you may experience one or more of the following reactions:
- Feeling very tired
- Nausea/vomiting
- Weakness
- Trouble breathing
- Chest pain
- Rapid heartbeat
- Headaches
- Dry mouth or constant thirst
- High blood pressure
- Dizziness or fainting
- Worsening allergies
- Signs of shock
- Blaming yourself or others
- Confusion
- Shorter attention span
- Flashbacks
- Trouble concentrating or loss of confidence
- Negative self-talk
- Reduced awareness
- Disturbing thoughts
- Nightmares
- Being easily distracted
- Short-term memory problems
- Feeling disoriented about time, place or people
- Frustration
- A strong need for others to understand what you experienced
- Anxiety
- Guilt or strong feelings for those involved
- Sense of loss
- Anger
- Denial
- Fear of losing control
- Irritability or agitation
- Depression
- Feeling overwhelmed
- Feeling isolated
- Difficulty controlling emotions
- Emotional outbursts
- Changes in activity level
- Trouble sleeping
- Smoking more than usual
- Being easily startled or constantly on alert
- Antisocial behaviour
- Withdrawing from others
- Changes in eating habits (eating more or less)
- Difficulty relaxing
- Restlessness or fidgeting
- Increased use of alcohol or other substances
- Changes in sex drive
Source: Critical Incident Stress Management (CISM) Program, Canada Border Services Agency - Pacific Region: CISM Mass Event Response Plan (2026).