Charities across the south say rising aviation fuel prices are putting pressure on their services.
Thames Valley Air Ambulance says 1 in 3 women receive no CPR before emergency crews arrive.
The Duchess of Edinburgh observed critical care training and unveiled a commemorative plaque.
Early CPR and defibrillation can double people's chances of survival if they have a cardiac arrest.
The charity, which provides critical emergency care, is called out an average of nine times a day.
The M4 in Berkshire was closed for several hours on Sunday following the incident near Reading.
Police confirmed the road had reopened following a crash involving a car and a motorcycle.
Thames Valley Air Ambulance and Child Bereavement UK will work together to support bereaved families.
