Medically trained police officers to patrol Tube network
Medics are to be used on the London Underground to help speed up the response when passengers fall ill.
Transport for London (TfL) said the move would enable faster response times to help reduce service delays.
Twenty British Transport Police (BTP) officers have been trained and have access to two fast response vehicles to enable them to reach incidents quickly.
TfL said a third of all delays on the Tube were passenger incidents, with ill people accounting for most of these.
The specially-trained officers will also assist any people trapped on trains in tunnels or at other locations.
The officers, who have undertaken an intensive four-week course in pre-hospital care paid for by TfL, will be on duty every day between 07:00 and 23:00.
They will be working at various locations as part of a year-long trial which starts on 28 May.
Nigel Holness, operations director at London Underground, said the introduction of medically-trained officers was "particularly important during the summer when we welcome millions of extra visitors from around the world".