Rescue blankets are medical devices made of a polyethylene terephthalate sheet coated with a thin aluminum layer. Blankets are used for protection against hypothermia in prehospital emergency medicine and outdoor sports, but totally different qualities are typical for these multi-functional tools. On the one hand, rescue sheets prevent hypothermia by reducing thermo-convection and diminishing heat loss from evaporation and thermal radiation. On the other hand, the sheets promote cooling by acting as a radiant barrier, by providing shade and even by increasing heat conduction when the sheet is in direct contact with the skin. As foils are watertight and windproof, they can function as vapor barriers and even as stopgap bivouac sacks. We evaluated three experimental studies, one on heat loss by rescue blankets according to surface color, one on transparency with ultraviolet radiation, high-energy visible light and visible light, and one on infrared radiation from rescue blankets. When evaluating the effects of different bands of the electromagnetic spectrum on rescue sheets, we focused on ultraviolet radiation (200–380 nm), high-energy visible light in the violet/blue band (380–450 nm), visible light (380–760 nm) and infrared radiation (7500–13,500 nm). Rescue sheets transmit between 1% and 8% of visible light and about 1% of ultraviolet B radiation (280–315 nm), providing sufficient transparency and adequate protection from snow blindness. Reflection of visible light increases detectability in search and rescue missions performed in good visibility conditions, while reflection of infrared radiation increases detectability in poor visibility conditions and provides protection against hypothermia.

Metallized rescue sheets are essential components in first aid boxes and professional emergency equipment for provision of thermal insulation. We investigated the transparency for visual light and the transmission of ultraviolet radiation and high-energy visible light in the violet/blue band of rescue sheets under laboratory conditions to evaluate the potential of blocking solar radiation during outdoor activities. An experimental study was performed using two commercially available brands of rescue sheets. Transmission of visible light and ultraviolet light was assessed by optometry. Single-layer transparency for visible light was between 1% and 8%. Transmission for high-energy visible light in the violet/blue band and ultraviolet A rays was between 1% and 13% for the single layer and between 0% and 3% for the double layer of the rescue sheets. Transmission for ultraviolet B rays afforded by each tested rescue sheet brand was between 0% and 1% for the single layer. Double-layer rescue sheets blocked 100% of ultraviolet B radiation. In conclusion, single layer rescue sheets were sufficiently permeable for visible light and diminished transmission for ultraviolet radiation and high-energy visible light in the violet/blue band to potentially protect from solar radiation if used for facial protection and as makeshift sun googles.

IntroductiondMetallic survival blankets are multifunctional medical devices frequently used to provide thermal insulation in sport and leisure activities and in emergency care. To assess further properties of survival blankets, we investigated their breaking strength under laboratory conditions.MethodsdAn experimental study was performed with 2 commercially available survival blankets used by emergency medical services. Breaking strength measured with a tensile testing machine was determined consecutively with 10 tests conducted per brand.ResultsdBreaking strength (mean±SD) of the tested brands was 3.8±0.4 kN, (range: 2.8e4.1 kN) and 4.0±0.5 kN (range: 3.2e4.6 kN). When using the windlass of a commercially available tourniquet for the longitudinally folded survival blanket, the windlass bent at a force of 0.8 kN; when using a carabiner, the force exceeded 3.6 kN before failure occurred in both blanket brands.ConclusionsdBoth brands of survival blankets show impressive tensile strength, indicating that they have the potential to serve as temporary pelvic binders or even as makeshift tourniquets when urgent bleeding control is needed.

Thermal imaging for unmanned aerial vehicles is used to search for victims in poor visibility conditions. We used a gimbal-mounted camera for thermo-radiation measurements of body temperature from persons covered with rescue blankets in the hibernal wilderness setting. Long-wave infrared radiation in the spectral range between 7500 and 13,500 nm was evaluated. Parts of this research have previously been published in a review on electromagnetic radiation reflectivity of rescue blankets (https://www.mdpi.com/2079-6412/10/4/375/htm). Surface temperature measurement was diminished by clothing, namely by 72.6% for fleece, by 82.2% for an additional down jacket and by 92.3% for an additional all-weather jacket, as compared to forehead temperature. Furthermore, we detected that a single-layer rescue blanket is sufficient to render recognition of a body shape impossible. With three layers covering a clothed body infrared transmission was almost completely blocked. However, rescue blankets increase visibility for thermal cameras due to high gradients in temperature. Conspicuously low temperatures from objects of 1 to 2 m length may indicate reflections from rescue blanket surfaces in a cold environment. Ideally, rescue blankets should be removed from the body to increase the chance of being located when using thermal imaging to search for victims in search and rescue missions.

Aerosols generated from chest compressions and ventilation attempts in patients with cardiac arrest may cause airborne infections. Accordingly, the interim international resuscitation guidelines have restricted basic life support by lay rescuers to compression only and the use of an automated external defibrillator during the COVID-19 pandemic. Although these measures may diminish the risk of infection for laypersons, the missing respiratory support can be detrimental for patients with hypoxia-related cardiac arrest. To overcome this shortcoming we want to introduce a special tool that allows ventilation during barrier resuscitation by laypersons. We hypothesize that the application of a device made of a polyvinyl chloride shield with a centrally installed S-shaped ventilation pipe with integrated filter can provide adequate ventilation while concurrently protecting patient and rescuer from airborne agents. Aerosols from air leakage are removed by adhesion and drainage below the barrier. No specific training other than basic life support is needed. We suggest that a tool of this kind be considered essential equipment and stored together with disposable gloves in public access locations.

BACKGROUND Open pneumothorax after a penetrating thorax trauma is a life-threatening disease with high mortality.An emergency application of a chest seal (CS) allowing the release of trapped air is the optimum initial therapy until surgical chest drainage is available.METHODS In a newly developed experimental porcine model of open pneumothorax, we tested 3 different materials regarding their applicability for acute treatment of sucking chest wounds in prehospital emergency care, namely a commonly used rescue blanket (RB), plastic foil from a gauze package (packing material), and a commercial CS. RESULTSAn ex vivo open pneumothorax model using a porcine chest wall and a vacuum-assisted drainage system was successfully established. RB segments sized 70 3 100 mm achieved significantly higher rates of successful sealing than plastic foils from a gauze package sized 100 3 100 mm when the devices were applied to the moistened chest wall and fixed on 3 sides (5/5 [100%] vs 0/5 [0%], respectively; P [ .002). Loosely fixed RBs efficiently released injected air (10/10 [100%]) and consequently sealed the wound in all cases (10/10).CONCLUSIONS RBs, applied wet, are appropriate CSs with good occlusive and adherence properties. Fixation on 2 sides of the dressing is sufficient to allow trapped air to exit while providing appropriate sealing of the chest wound. RBs were superior to plastic foils from a gauze package and were seen to function as a potent makeshift CS when no commercial CS is available.

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