The following article, submitted in two complementary parts deals with an important and also modern concept developed under the name of damage-control surgery. Physiopathologically, the multiple injured patient is characterised by the probable, not just possible, appearance of the „blood’s vicious cycle” of hypocoagulability, hypothermia and acidosis with death as a result. The first part of the article addresses the changes that are the reasons and the basis for applying damage-control surgery. Hypothermia is a direct result of trauma and patient’s exposure to it but can also emerge throughout transportation, evaluation, emergency and surgical procedures to which the patient undergoes. Surgical procedures are directly a source that decreases the core temperature. While blood losses accompany trauma for certain and affect clot formation, the patient’s coagulation system is impaired by these losses and the dysfunction is further enhanced by hypotermia, different mechanisms being involved. The third lethal component is acidosis. While being at first metabolically produced because of tissular injury, it is further enhanced by the other two elements. From a practical point of view, hypothermia and hypocoagulability can be though, more teoretically addressed, acidosis is more difficult to correct. As fav as the emergency specialist is concerned for the moment, the best solution to deal with this deadly triad is to prevent it. Damage-control surgery is just one type of measure in the process of prevention.