Explain when a bee sting could be life threatening and what action should be taken for prevention and for first aid?

Bee stings can cause a fatal reaction called anaphylaxis in people who have a severe allergy to bee venom. It is possible to have the same reaction to foods and medicines (peanuts and shellfish are also common causes of anaphylatic reactions). The effects are nearly immediate -- swelling of the neck and face, sweating, difficulty breathing and hives are among the most common signs. Many people with severe Allergies, especially bee stings, carry a device called an Epi-Pen. An Epi-Pen is a dosage of a powerful drug, epinephrine, which counteracts an anaphylactic reaction. To use it, remove the safety cap and simply press the needle end firmly against the victim's thigh, about midway between the knee and hip. The spring-loaded needle will automatically extend, delivering the epinephrine into the muscle where it will be rapidly transferred into the bloodstream. The effect of the epi-pen is temporary, however, and the person must still get medical attention quickly.