HEMS teams (helicopter) should be called in the following situations:
time needed for transport by air from the scene/place of call in a state of emergency, to the proper medical facility is shorter than time needed to transport by other means and might be advantageous for further treatment;
there are circumstances which might prevent or significantly delay others means of rescue to the victim in the state of emergency (eg.: topography)
mass events (sudden threat, for which the need for medical rescue operations exceeds the capabilities of means present at the scene, and there is a need for segregation understood as setting treatment – transport priotities);
states of emergency (other than those specified below) requiring urgent care of a medical rescue team;
unconscious patient;
sudden cardiac arrest;
acute cardiological conditions;
hypertensive crisis;
stroke;
traffic accidents;
fall from a height;
burying, avalanche;
polytrauma;
head injury requiring urgent neurosurgical intervention;
spinal injury with paraplegia, quadriplegia or symptoms lateralization;
penetrating trauma to the neck, chest or abdomen;
two or more fractures of long bones;
severe pelvic injury;
traumatic amputation of limbs;
II° and IIIº burns that cover more than 20% body surface area burns, suspected respiratory burns, electric burns, explosions and fires;
hypothermia;
drowning.
There exists a possibility of not completing the rescue mission because of the threats regarding the flight safety, as well as operational and legal limitations