PHASE-change technology used by the military is today being used for the first time by London's Air Ambulance to carry blood on board its aircraft and cars. The new initiative is expected to save many lives.
Previously medical teams have been unable to transfuse blood at the scene of the incident as it must be stored at a specific temperature in special containers. Normal saline has been used as an alternative but, as it does not carry oxygen, it is not the ideal resuscitation fluid. Blood carries oxygen which is delivered to major organs including the brain. A pre-hospital blood transfusion may improve the patient's chance of survival.

The problem has been solved by UK-based controlled temperature packaging specialists SCA Cool Logistics. Its Credo packaging uses a combination of passive vacuum insulated panels and phase-change materials to maintain the contents within the required temperature range. The re-usable packaging is available in all temperature ranges: +2°C to +8°C, +15°C to +25°C, -15°C to -25°C. Temperatures to -40°C or colder are also available.

Each box carried on board the aircraft and rapid response cars will carry four units of O negative (emergency) blood.