IndexOverviewWhat are Instant Hot and Cold Compresses?Brief History of Hot CompressesBrief History of Cold CompressesThe use of cold for therapy has evolved in 3 phases:Uses and Benefits of Hot CompressesThe Chemistry of Instant Hot and Cold CompressesCalcium Chloride: Magnesium SulfateCrystallizes at High Temperature Urea: CO(NH2)2Environmental ImplicationsEnvironmental Concerns of Instant Hot and Cold CompressesOverviewWhat is it?Brief HistoryUsesHow it WorksEnvironmental Benefits and ConcernsCurrent Research and Future DirectionWhat are Instant Hot and Cold Compresses Packages?Plastic bags containing different chemical compoundsSay no to plagiarism. Get a tailor-made essay on "Why Violent Video Games Shouldn't Be Banned"? Get an original essayWhen squeezed, hot compresses create an exothermic reaction releasing heatCold compresses create an endothermic reaction that absorbs heat and becomes coldThese can be used for various types of injuries or pain Speaker Notes: Instant hot and cold compresses are pouches plastic (similar to those used for an ice pack), which contain various chemical compounds. When these are squeezed, hot compresses instantly create an exothermic reaction releasing heat, while cold compresses instantly create an endothermic reaction that absorbs heat, becoming cold. These are generally used to treat various types of injuries and pain. Brief History of Heating Compresses In Japan around 1603-1868, many heated stones, wrapped them in cloth to provide an application of soothing heat. These early "heating packs" required an external source of heat such as fire, so they were not very practical In 1911, the first electric heating pad ("El Warmo") was designed by Earl Richardson Problems such as fire hazard arose This was due to old threads that came into contact with the fabric Led to the development of a heating pad that required no heat source or electricitySpeaker Notes: In Japan from the early 1600s until the mid-1800s, a Popular method of heat therapy consisted of heating stones using an open fire and wrapping them in cloth to apply to the affected area. While this was effective to some extent, it required fire as a heat source, which was not always available, making this method impractical. It wasn't until 1911 that Earl Richardson designed the first electric heating pad which he called “El Warmo”. This form of heat therapy was more practical than the previous one and was more accessible as it only required electricity. However, problems arose from this, such as old threads coming into contact with the fabric, creating a fire hazard. This led to the development of an instant heat pack that required no external heat or power source. Brief History of Cold Compresses The use of cold for therapy evolved in 3 phases: 19th century - Natural ice was used for cold therapy (e.g. snow to numb soldiers in 1812) 1890 to 1950 - Began experimenting with natural ice substitutes from 1950 to present - Chemical cold compresses were developed Speaker Notes: The use of cold therapy for swelling, injuries and numbness dates back to the 19th century during war. At the time, doctors used natural ice or snow to numb soldiers. From here, cold therapy evolved and people began using natural ice substitutes. Ice was made at home by using an ice cube tray and placing the ice in a cloth or plastic bag. Subsequently, compresses were createdice gels that required freezing before use. Finally, chemical cold compresses have been developed that are instantaneous and do not require an external source of cooling. Uses and Benefits of Hot Compresses Heat increases blood flow to restore movement of damaged tissue Reduces stiffness and joint pain Relaxes tight muscles, causes tissues to relax Decreases pain caused by muscle tension or spasmsInstantly hotPortable and easy to useSlide 9 : Uses and Benefits of Cold Compresses Reduces blood flow to a particular area, reducing inflammation and swelling Can temporarily reduce nerve activity which can relieve pain Instant, ready to use Great for emergencies Small, portable and safe The Chemistry of Compresses instant hot and cold Endothermic and exothermic reactions occur as a result of salt dissolving in water Salt dissociates, causing hot compresses to release heat and cold compresses to absorb heat How this happens depends on the chemicals used Speaker Notes: Most instant compresses hot and cold compresses work by dissolving some sort of salt in the water. When this dissociation occurs (see for example figure 1) endothermic or exothermic reactions take place. The chemical compounds used differ depending on the brand and type of hot and cold compresses. Calcium Chloride: Speaker Notes: The simplest warm compresses use calcium chloride. When you follow the instructions on the hot compress (e.g. “squeeze here”), the water mixes with the calcium chloride, which then dissociates into its Ca2+ and Cl- ions (figure 2), triggering the release of heat as shown in the figure potential energy diagram for this exothermic reaction. The temperature of the hot compress can reach 90 degrees almost instantly. Speaker Notes on Magnesium Sulfate: Magnesium sulfate also produces a large amount of heat when dissolved in water. The process that occurs within a hot compress with magnesium sulfate is very similar to that of calcium chloride. Inside a magnesium sulfate hot compress, there is a small bag filled with water and is surrounded by magnesium sulfate in crystal form. When the small bag breaks, the crystals begin to dissolve in the water (figure 3), causing an exothermic reaction as shown in the potential energy diagram. Crystallizes at high temperature High boiling and melting point Speaker Notes: The process that takes place in a hot compress containing sodium acetate is slightly more complicated than the previous two, however it is more effective since they are reusable. Since sodium acetate freezes at 54 degrees and will remain in solution at temperatures below the point of crystallization. These heat packs contain a solution of sodium acetate and water, as well as a small metal disc isolated from the solution. To start crystallization, pressure can be applied to the small metal disk, causing some molecules to crystallize. As a result, the rest of the molecules jump to solidify later, causing the temperature to increase up to 54 degrees (ex figure 5). These types of heat packs can be reused by simply boiling the solution back to a liquid state and repeating the process (figure 4). Speaker Notes: Ammonium nitrate has traditionally been the most common chemical found in instant cold compresses. Inside the cold compress, a small pocket of water is kept separate from the chemical. When the bag is broken, the dissolution of NH4NO3 begins and divides into its ions as shown in figure 6. The solution absorbs.