This report describes how so called thermobaric warheads function and their effects. These types of warheads are especially designed for combat operations in built up areas. The report further gives some base data for continuing work on protection of soldiers from these effects. Development of these kinds of weapons is going on in Russia, but Great Britain and USA is also developing their own. They are widely spread throughout the world and present a threat to soldiers in peacekeeping missions under the UN command. From this investigation it is obvious that the most important effect is the high temperature and its duration, especially in confined spaces. The most severe effect is when hot gases are inhaled which destroys the lungs leading to suffocation and death.