There are medical alert devices available in a range of price points and for various conditions ranging from heart trouble to asthma, allergies to epilepsy and are an integral part in saving lives every day.  The device should be work prominently on the body so it may be easily viewed by paramedic teams.  Alternately, you can choose a more elaborate device that is connected to a home invasion type of alarm, which summons help at the push of a button.  These are worn on bracelets or necklaces just like more traditional types.  The alarm type devices will also notify family members.