Shock is the body’s response to stress.
The stress can be relatively minor - like a cut finger, fear or fright - or it may be life threatening, like major blood loss, extensive burns or serious dehydration causing severe shock.
In its response to shock, the body quickly increases oxygen supply, which then requires the heart to work harder at circulating that oxygen to the vital organs: the brain, lungs and heart muscle itself.
This increase in oxygen supply and heart rate can cause irritability, confusion, rapid breathing, weak and rapid pulse, pale, cold clammy 
skin, nausea or vomiting as the blood leaves the digestive system for the vital organs. Fainting is a common response to minor shock. In severe shock, the body may not be able to manage the increase in circulation, and the system may well collapse, causing loss of consciousness.
If someone is showing these signs in response to a minor injury or major loss of blood or dehydration.
1. Assess the patient’s conscious state and check for injuries, including bleeding or burns, but ensure breath is normal before treating these.
2. If conscious or semi-conscious and breathing normally, place the patient in recovery position and monitor closely. Cover with a blanket to maintain body heat. Loosen tight clothing and avoid food or drink.
3. If their conscious state deteriorates, call Triple Zero (000) or mobile 112 and prepare to start CPR.
4. If the patient is conscious, reassure and keep them calm while waiting for assistance or until they recover.
5. If the patient faints, raise their legs and monitor their conscious state as above.
Find out more about Basic Life Support resources and aids here.