Heat & Muscle performance---no reason for death or medical emergencies in HS Football practice

But what does overheating have to do with fatigue in the first place? Much of the lab's recent research can be summed up with Grahn's statement that "temperature is a primary limiting factor for performance." But the researchers were at a loss to understand why until recently. In 2009, it was discovered that muscle pyruvate kinase, or MPK, an enzyme that muscles need in order to generate chemical energy, was highly temperature- sensitive. At normal body temperature, the enzyme is active – but as temperatures rise, some of the enzyme begins to deform into the inactive state. By the time muscle temperatures near 104 degrees Fahrenheit, MPK activity completely shuts down. There's a very good biological reason for this shutdown. As a muscle cell increases its activity, it heats up. But if this process continues for too long, the cell will self-destruct. By shutting itself down below a critical temperature threshold, MPK serves as an elegant self-regulation system for the muscle. "Your muscle cells are saying, "You can't work that hard anymore, because if you do you're going to cook and die,'" Grahn said. When you cool the muscle cell, you return the enzyme to the active state, essentially resetting the muscle's state of fatigue. The version of the device that will be made available commercially is still being tweaked, but the researchers see applications for heat extraction in areas more important than a simple performance boost. Hyperthermia and heat stress don't just lead to fatigue – they can become medical emergencies. "And every year we hear stories about high school athletes beginning football practice in August in hot places in the country, and there are deaths due to hyperthermia," said Heller. "There's no reason why that should occur."

Space suit & MMU

Apollo space suit

More on cooling suit

February 1, 2008 — Safety scientists used principles of physiology to help keep firefighters cool in the high temperature environments they often encounter. Traditional firefighting gear considers the heat of the fire, but not the body heat generated by the firefighter. By running tubes of circulating cool water close to the skin, where the body brings warm blood, the suit pulls more heat away from the body. The suit focuses on areas where the body transfers the most heat – the scalp, chest, and forearms. See also: Matter & Energy Civil Engineering Construction Weapons Technology Materials Science Physics Nature of Water Reference Firestorm Combustion Gas laws Sulfur hexafluoride Firefighters battle flames and smoke in gear that is specially designed to insulate them -- even when temperatures exceed one thousand degrees. But the very same life-saving equipment a firefighter dons may be putting him or her at risk -- by raising body temperatures to dangerous levels. Now researchers are developing a system to cool them off while they're smack dab in the middle of the fire. Firefighting is dangerously hot work. The heat from a house fire can reach over 11-hundred degrees Fahrenheit. "It causes you to build up body heat," Jon Williams, Research Physiologist at the National Institute for Occupational Safety and Health told Ivanhoe. But soon -- firefighters may add another layer of protection that will subtract body heat. This is a cooling suit -- a spandex undergarment, lined with plastic tubing. Physiologists say when a firefighter starts to work hard. His body gets rid of heat by moving warm blood into the skin. These tubes allow cool water to carry the heat away from the firefighter's body. The suit is designed to concentrate on areas where the body transfers the most heat. "The scalp, the areas of the chest, the forearms. Where you get more heat transfer in those areas than you would if you were cooling another area of the body," Williams said. At the National Institute for Occupational Safety and Health Lab, volunteers test the suit -- by walking on a treadmill -- to raise the person's core body temperature. For this test, researchers turned on the water transfer system. The volunteer's temperature barely changed. For the second test, the cooling system was not turned on. After just a few minutes, the monitor showed a temperature spike -- his body went from ninety-seven -point-seven degrees Fahrenheit to ninety-eight-point- seven. So now, scientists hope firefighters can douse flames … and keep cool all at the same time. Hotter Houses: House materials inside and out have changed dramatically over the last three decades -- most are now made from synthetic materials rather than wood or metal. So today's blazes produce two to three times as much energy as a typical fire did in 1980, and most of that energy is released as flammable gases. The invisible gases produced in a fire can be much more dangerous than the flames, especially in enclosed spaces. Newer buildings are well insulated and tightly sealed. That means gases in newer buildings can become superheated, flammable and highly mobile. The result is extreme fire behavior, marked by life-threatening backdrafts, flashovers and gas explosions. Scores of firefighters die each year because they use old outdated methods against this volatile mix of physics and fire gases. The American Industrial Hygiene Association and the National Institute for Occupational Safety and Health contributed to the information contained in the video portion of this report.

Liquid cooled garment

Techniques for cooling extreminities

https://www.glendaleaz.com/HealthCenter/documents/Coolingffforearms.pdf


Sent from my iPad

Cooler suit will revolutionize Fire Fighting

During the summer months quite often during a major fire you see all the firemen suffering from over heating & heat exhaustion. This suit capability has been demonstrated by the space program. It will eventually be utilized by all major fire departments. Also, the heat removal device for extreminities will be use during rest periods to restore muscle capability.

Inexpensive demo kit available soon

Purpose of kit will be to demonstrate the heat transfer aspect involved in the liquid cooled garment.

Amazing Heat Sucker

New hardware coming out which sucks(removes) heat from extremenities by placing slight vacuum on them & circulating coolant. This improves muscle performance significantly and can be used in conjunction with the firemancooler during rest periods. By taking advantage of specialized heat-transfer veins in the palms of hands, they can rapidly cool firemans core temperatures and dramatically improve exertion recovery and performance. These networks of veins, (arteriovenous anastomoses) seem exclusively devoted to rapid temperature management. They don't supply nutrition to the skin, and they have highly variable blood flow, ranging from negligible in cold weather to as much as 60 percent of total cardiac output during hot weather or exercise.

Fireman cooler suit

This system will follow the theory outline in the Liquid Cooled Garment ( LCG )article in the above post. Firemen dressed in appropriate configuration lcg will be cooled by cool water provided by source water or by closed loop water pumped through heat exchanger in contact with dry ice ( self contained module). This system will have application to people in high heat conditions & to people with certain medical conditions that require special cooling.

Liquid cooled Garment

From Wikipedia, the free encyclopedia A man wearing a Liquid Cooling and Ventilation Garment for the Space Shuttle/International Space Station Extravehicular Mobility Unit (EMU) A Liquid Cooling Garment (LCG) is a form-fitting garment that is used to remove body heat from the wearer in environments where evaporative cooling from sweating and open air convection cooling does not work, or the wearer has a biological problem that hinders self-regulation of body temperature. A Liquid Cooling and Ventilation Garment (LCVG) has additional crush-resistant ventilation ducts, which draw moist air from the wearer's extremities, keeping the wearer dry. In a fully enclosing suit where exhaled breathing air can enter the suit, the exhaled air is moist and can lead to an uncomfortable feeling of dampness or wetness. While this technology is most commonly associated with space suits, it is also used in a wide range of Earth-bound applications where open-air cooling is difficult or impossible to achieve, such as fire fighting or working in a steel mill. Contents  [hide]  1 Technology 1.1 Garment and tubing 1.2 Heat exchanger 2 Space applications 3 Images 4 References 5 External links [edit]Technology There are typically two parts to a liquid cooling garment: the heat collection garment and tubing a heat exchanger for removal of heat from the circulated fluid [edit]Garment and tubing The garment is typically a close-fitting non-stretching fabric or a tight-fitting elastic fabric, with flexible tubing sewn onto the fabric. A single-layer of fabric may be used, with the tubing either on the inside directly contacting the wearer's skin, or on the outside separated by the fabric. If two layers of fabric are used, stitched channels can be formed which enclose the tubing between the two fabric layers. Where flame resistance is needed, the garment may be constructed out of materials such as nomex. The tubing is typically a few millimeters in diameter, and may be made out of any number of flexible plastics such as polyvinyl chloride (PVC) or silicone. Smaller diameter tubing permits a higher degree of garment flexibility, but at a cost of lower heat absorption capacity, and increased pressure needed to push liquid through the tubing. When a large area needs to be cooled or the external environment also heats the tubing, a single long tube may not be enough because the liquid becomes saturated with heat and can not cool any further. Making the liquid much colder is not an option since it leads to uncomfortable coldness where the liquid enters the tubes. Instead, multiple parallel tubes are used to increase the volume of liquid available to absorb heat. Skin coverage and tubing density can vary depending on the application. The garment may simply be a short-sleeved shirt, or it may be a full-body suit covering the arms and legs. Where the heat removal requirement is low, the tubing may be spaced several centimeters apart across the garment surface. Where there is a very large amount of heat to remove, the tubing can be arranged in a dense grid with no gaps between the tubes. [edit]Heat exchanger For portable earth bound applications, the heat exchanger for cooling the liquid can be very low-tech, consisting simply of a container for holding ice, and an electric pump to circulate water from the container through the tubing. The return water is cooled by the melting ice, and again pumped through the tubes. Regulation of flow is done by varying pump speed or using an adjustable flow valve. Ice storage can be achieved using a belt-pack, a backpack, or a duffel bag, depending on the length of time needed for the cooling system to operate between refilling the ice storage. In situations where the wearer must stay in place inside a vehicle, heavy but long-term-operation heat exchangers can be used, such as a refrigration system to cool the liquid. When the user's movement is partially hindered through the use of a life-support umbilical, cooling liquid can also be supplied via the umbilical. [edit]Space applications Astronauts commonly wear a Liquid Cooling and Ventilation Garment in order to maintain a comfortable core body temperature during extra-vehicular activity (EVA). The LCVG accomplishes this task by circulating cool water through a network of flexible tubes in direct contact with the astronaut's skin. The water draws heat away from the body, resulting in a lower core temperature. The water then returns to the Primary Life Support System (PLSS), where it is cooled in a heat exchanger before being recirculated. In an independent space suit, the heat is ultimately transferred to a thin sheet of ice (formed by a separate feed water source). Due to the extremely low pressure in space, the heated ice sublimates directly to water vapor, which is then vented away from the suit. In a dependent space suit (such as the ones used in the Gemini program or within lunar orbit on the Apollo program), the heat is carried back to a host spacecraft through an umbilical connection, where it is ultimately radiated or sublimated via the spacecraft's own thermal control system. Because the space environment is essentially a vacuum, heat cannot be lost through heat convection, and can only be directly dissipated through thermal radiation, a much slower process. Thus, even though the environment of space can be extremely cold, excessive heat build-up is inevitable. Without an LCVG, there would be no means by which to expel this heat, and it would affect not only EVA performance, but the health of the suit occupant as well. The LCVG used with the Apollo/Skylab A7L suit could remove heat at a rate of approximately 586 watts.[1] The LCVG used with NASA's Extravehicular Mobility Unit is primarily constructed of spandex, with a nylon tricot liner.[2] The tubes are made of polyvinyl chloride. [edit]Images Apollo LCVG Old Orlan LCVG Current Orlan LCVG [edit]References ^ Carson, Maurice A.; Rouen, Michael N., Lutz, Charles C., and McBarron, James W. II. Biomedical Results of Apollo - Section VI - Chapter 6 - Extravehicular Mobility Unit. Lyndon B. Johnson Space Center. ^ Freudenrich, Craig C.. "How Spacesuits Work". How Stuff Works. Retrieved 2007-01-18. [edit]External links Picture of an LCVG List of EMU components - NASA Quest Hamilton Sundstrand [hide] v t e Space suits USSR / Russia SK-1 Berkut Yastreb Krechet-94 Strizh Sokol Orlan United States Navy Mark IV Gemini MOL A7L Shuttle Ejection Escape Suit LES ACES EMU China Shenzhou IVA Haiying Feitian Developmental Mark III I-Suit Space activity suit Constellation Space Suit Components Hard Upper Torso (HUT) Liquid Cooling and Ventilation Garment (LCVG) Maximum Absorbency Garment (MAG) Primary Life Support System (PLSS) Thermal Micrometeoroid Garment (TMG / ITMG) Related topics Extra-vehicular activity (EVA) Astronaut Propulsion Unit Pressure suit View page ratings Rate this page What's this? Trustworthy Objective Complete Well-written I am highly knowledgeable about this topic (optional) Submit ratings Categories: Human spaceflightSpace suit components Create accountLog inArticleTalkReadEditView history