Jennifer Matthews: In an emergency room, a split second decision can mean the difference between life and death.

John Halamka: So many emergency physicians have to operate blind. We have to make medical decisions not knowing what kind of medicines you take or allergies you have.

Jennifer Matthews: Harvard doctor John Halamka says this radio-frequency identification chip may solve that problem. He had it implanted in his upper right arm. A scanner reads an identification number. Those 16 digits are then entered into a secure website where his medical history is stored. EMT worker Brian Orsatti says the chip could help emergency workers.

Brian Orsatti: One of the big things is if you ever have some type of trauma patient where they come in and they're unable to give their information and or their medical history.

Jennifer Matthews: Anyone can get the chip and while some patients may be concerned about privacy issues, Doctor Halamka says the benefits are clear.

John Halamka: I am a rock climber, and I believe if I fall off the edge of a cliff, and you find me unconscious the comfort of being able to scan me and figure find out who I am outweighs my concern for privacy.

Jennifer Matthews: The chip is encased in unbreakable glass and is about the size of a grain of rice. The procedure is done with anesthesia and is relatively pain-free.

John Halamka: It's like putting a knitting needle under your skin.

Jennifer Matthews: But in this case, he says getting something under your skin is a good thing. This is Jennifer Matthews reporting.