Influence of different types of the internal system of the ballistic helmet shell on the thermal insulation measured by a manikin headform

Abstract The head is a part of the body whose temperature influences not only physiological parameters of the whole body but also the perception of a thermal environment and psychomotor parameters of a human. For this reason, it is important to prevent the head from overheating and to use head covers which render it possible to release heat from head surface to the environment. There exist a number of professions where head covers serve as protection against injuries caused by an accident, trip, or striking the head against a fixed or protruding object. Ballistic helmets are one of such elements, their crucial parameter being ballistic resistance against dynamic deflection caused by a bullet or bullet-fragment. To enhance security and comfort of use of ballistic helmets internal systems are used underneath. Their character depends on the type of a helmet. Thermal insulation is a parameter defining the amount of heat which can be released from a human body to the environment using all types of body covers. The objective of the research was to compare thermal insulation of 4 ballistic helmets with different types of the internal system. The conducted research showed the lowest thermal insulation was noted for the helmet D (with a suspension system made of cotton technical straps), the highest for the helmet B (with multi-segments pads, made of polyurethane). As the structures of the helmets did not differ significantly, it can be assumed that a decisive influence on thermal insulation was exerted by the internal system and the application of a suspension system results in better heat release than it is the case with the padding system. Relevance to industry The knowledge about the thermal insulation of the ballistic helmets and the effect of diversity of internal system on their thermal insulations provides information that extends current understanding of the risks faced by soldiers using ballistic protections. This information may be particularly useful in the design and implementation of the different kind of head protections.