Firefighters face many dangers during interventions. Every fire is an uncontrolled event and as such highly unpredictable. Its development is influenced by many factors and it is very difficult to include all of these factors in one general model that would fully understand and describe the behavior of a fire. When it comes to indoor structure fires, there are dangers due to the impossibility of free development of fire and exchange of energy with the environment. Heat and smoke are not sufficiently dissipated, the amount of oxygen is reduced and dangerous compounds which can additionally ignite begin to form, which can cause a small fire to quickly escalate into a devastating flaming torch. Such events have led to numerous deaths of firefighters around the world. In order to minimize the risk, it is necessary to understand the origin and behavior of these phenomena. Only then can the knowledge be used to create better quality personal protective equipment, effective training and extinguishing methods by which firefighters can put out fires more safely and efficiently. Based on the above, the basic elements of tactical approaches to extinguishing indoor fires and protection measures are presented.