If the level of sugar in the blood goes too low (hypoglycemia) or too high (hyperglycemia) a diabetic emergency can occur. Since hyperglycemia takes longer to develop it is less likely to result in a diabetic emergency.
What to look for: Changes in the level of consciousness, Changes in behaviour, Rapid Breathing, Cool, seating skin skin that is paler that normal, appearance of intoxication, feeling and looking ill
What to do: Call EMS/911. If the person is conscious and knows it is a diabetic emergency offer them a sugary drink. If their condition improves have them have a complete meal. Never give an unconscious person something to drink. To learn more take a Canadian Red Cross First Aid course.