+The results obtained from the study on thermal trauma were summarised on the base of histological, electron microscopic, immunologic and toxicological investigation methods. Shock during burning induces disturbances in the microcirculation. The great clinical significance of the alterations in lungs are stressed upon, manifested in a disorder of blood-gas barrier, permeability of the membranes of capillaries and cells, leading to acute pulmonary insufficiency. One of the probable mechanisms of anemia advancing after burns is described, that is due to the toxic effect of serum. Complement-fixation antibodies are found in the patients with burns, suggesting the involvement of autoimmune mechanisms in the course of the disease. The disturbed microcirculation has an unfavourable effect on the regeneration of wounds, leading to destruction of epithelial regeneration, disturbing the processes of revascularization of skin transplant, having an effect on the immune reactions of organism. Sepsis is discussed, with particular attention paid to that induced by Pseudomonas aeruginosa. In would cachexia some changes in the wounds are pointed to as well as sclerotic and atrophic processes in some internal organs, being usually irreversible. The reversibility if sclerosis in hypertrophic cicatrix and keloid is discussed, stressing on the cellular and extracellular mechanisms, involved in that process.