BOSTON — The need for emergency medical air transport is not always a matter of an exotic trip gone awry. Many families want to move a relative from a distant hospital or facility to one closer to where they live. For these and other reasons, the demand for air ambulance service is growing fast, reports the March 2007 issue of the Harvard Health Letter.

Some commercial airlines reserve space for a stretcher and medical personnel in the back of the cabin, but many are no longer providing that service. With an air ambulance, the patient is flown on a small jet outfitted with some of the equipment you’d find on a ground ambulance, with medical personnel onboard. The expense is enormous. Companies usually charge a base fee, a separate fee for medical personnel, and then mileage. A trip from Florida to Boston will cost at least $10,000; from Africa, at least $50,000.

You can buy travel insurance that will cover air evacuation services, although the coverage may be limited to transportation to the "nearest appropriate facility." An alternative to travel insurers are membership organizations such as Global Rescue and MedJet Assist. With these you aren’t restricted to the "nearest appropriate facility," but there are other limitations.

The Harvard Health Letter suggests that if you’re hiring an air ambulance directly, the best place to start looking for a reliable company is www.camts.org, the Web site for the Commission on Accreditation of Medical Transport Systems. Ask the following questions:

• Does the operator have valid certification and current insurance?

• Is the medical equipment suitable?

• How experienced are the pilots and medical personnel?

• Can you provide references from previous customers?