Used to describe something that endangers the continued life of the subject.The life-threatening illness caused him to be rushed to the hospital, where doctors worked around the clock to save his life.
2013, Nicholas Watt and Nick Hopkins, Afghanistan bomb: UK to 'look carefully' at use of vehicles (in The Guardian, 1 May 2013)http://www.guardian.co.uk/world/2013/may/01/afghanistan-bombs-look-vehiclesThe MoD said the injured men received immediate medical attention and were evacuated by air to the military hospital at Camp Bastion, but three could not be saved. Next of kin have been informed. The other soldiers hurt are not thought to have life-threatening injures.