EXOTHERM TECH INFO

ABOUT "EXOTHERM" TECHNOLOGY AND THE BENEFITS OF PERSONAL COOLING

"CONTROLLED TEMPERATURE" EXOTHERM TYPE TECHNOLOGY

Although phase change materials have been utilized for decades, it has only been recently recognized that the benefits of these controlled temperature compounds demonstrate excellent results when used as personal body cooling or cool therapy devices and in stabilizing the surrounding temperature of inanimate objects (equipment). Overwhelming acceptance within the medical community has successfully proven that effective use of optimum temperature cooling (and warming) phase change formulations in anatomically designed products for acute and chronic injuries, post-operative recovery, and long-term maladies will significantly reduce rehabilitation time and return to function of the affected area.

Cool Zone's constant temperature exotherm type technology utilizes non-toxic, non-carcinogenic blends of crystalline alkanes that possess attributes of low chemical reactivity with extremely high stability due to their molecular structures and bonding properties. Each blend yields a substance that melts or solidifies at a specific preset temperature and remains at that temperature for a predetermined time. Each blended formulation is then encapsulated in a proprietary copolymer film in anatomical configurations that are user friendly for humans and animals. Cool Zone's technology utilizes blends from 42 degrees Fahrenheit to 150 degrees Fahrenheit for a myriad of cooling/warming applications.

Unlike frozen water or gels, cool temperature alkanes (45degF - 60degF) expel energy at a constant temperature during their transition from a solid to a liquid; consequently, the melting and freezing point of these alkane blends are the same. As it is as common knowledge, water absorbs energy more quickly due to its high thermal transfer properties (heat of reaction). Water, when it makes a phase change to ice, absorbs energy at a rate of X and expels this same energy at the same rate of X during its transition back from a solid (ice) to a liquid (water). Alkanes, on the other hand, absorb energy at a rate of X when making a phase change from their liquid state to their phased solid state, but they expel this absorbed energy at a much lower rate when transitioning back from their energized solid state to their liquid state. In some instances, this poor release of energy makes these chemicals ineffective for some equipment use. However, when it relates to cooling the body of a human or animal, or for use in cryotherapy, this rate of energy release can be as much as three times the rate of water for the same volume of alkanes. Hence, the benefactor of these "controlled temperature" alkanes for cooling experiences a much longer cooling cycle than can be experienced with ice or gels of the same volume or weight.

PRATICAL APPLICATION OF EXOTHERM TYPE PHASE CHANGE TECHNOLOGY FOR PERSONAL COOLING
For personal cooling, the passive nature of these "controlled temperature" alkanes offer numerous positive attributes when compared to other cooling technologies. Their superlative features are simplicity, portability and quick charge time (~15-30 minutes). Quick charge and recharge of ~15-30 minutes in a medium of ice and water provides ease of use and mobility in the field for military and civilian personnel. Alternate methods of refrigeration may also be used, where charge time is also minimal when compared against charging times for other technologies. Nonetheless, when electricity is impractical, a passive means of charging phase change materials requires minimal effort and time. Whereas, ice and gel packs, utilized in both passive and mechanical circulatory systems, require several hours in temperatures below 0degC/ 32degF to charge. Freezing mediums further require the accessibility of electricity, not always available for in-field use or special situations.

PUBLIC AND SAFETY CONCERNS
Of paramount importance, phase change technology utilized in personal body cooling greatly reduces the health risks associated with heat related illnesses and is extremely effective for prolonged cryotherapy due to its delivery of safe, constant higher temperatures of 50-53degF (10 - 12degC), depending upon application. Medical experts cite the optimum temperature range for heat abstraction and prolonged cryotherapy as 46degF to 54degF. Prolonged or direct skin contact within this temperature range thwarts the onset of negative physiologic reactions, even at the cellular level. Temperatures of 46degF - 54degF (7.8deg - 12.2degC) do not cause constriction of the blood vessels (vasoconstriction) or damage to the superficial tissues as the frostbite hazards associated with the temperatures of ice and gel. Prolonged exposure to the skin and superficial tissue by ice and gel can readily cause crystallization of the skin, frostnip, ice burns, frostbite and hypothermia. When ice and gel are used to regulate body temperature, a caveat exists. Too cold of temperatures applied directly to the skin actually cause localized vasoconstriction, further hampering normal bodily cooling mechanisms incited by the hypothalamus in the brain and central nervous system (CNS). If using ice or gel for cryotherapy, the same warning applies, localized vasoconstriction causes oxygen deprivation to the affected area inciting secondary hypoxia, further slowing recovery and rehabilitation efforts.

THE PHYSIOLOGICAL BENEFITS OF USING CONTROLLED CONSTANT TEMPERATURE
Based on substantial medical research, the blended alkane temperature of 50-53degF for specific use within the cooling vests has unequivocally proven its effectiveness in greatly reducing the symptoms and effects associated with heat related illnesses. Primarily, this optimum temperature does not cause vasoconstriction or the "thermal shock syndrome" generally felt when exposed to the cold temperatures of ice and gel. Thermogenesis (rapid heat production through shivering) is not required when this higher temperature is held in close contact (thermal communication) with the body. Rather, this temperature allows for quick acclimatization, accompanied by a comfortable cool sensation felt on the peripheral skin areas.

Acting as a heat sink, the cool temperature abstracts excess body heat gained through metabolic activity and/or micro-environmental temperatures created when donning personal protective apparel. The blood carried throughout the peripheral vessels and surrounding soft tissues expel the latent heat and become cooler as more and more heat is abstracted from the surface area. Hence, recirculating cooler blood back throughout the venous return thwarts additional concomitant hyperactivity required to meet the demands of thermal regulation. As cooler blood continually irrigates the cardiovascular system, less metabolic energy is required, slowing the activity of essential body vitals (blood pressure, heart rate, pulmonary output of increased oxygen demands) as well as the latent heat of vaporization (sweating). As sweating wanes, cellular metabolic activity is reduced and less electrolyte fluids and precious minerals are forfeited resulting in a prolonged endurance factor. Since no vascular constriction is occurring, proper oxygen flow is maintained for optimum muscle function, brain activity and CNS functions.

Akin to the radiator of an engine, the optimum temperature of 50-53degF is the cooler receptor absorbing heat from the medium closest in proximity (the human body). In this example, as the body's engine cools, less heat needs to be expelled and less stress is placed on the engine itself. Clearly, the engine and its ancillary bodily functions operate more smoothly. As less hyperactivity is exacted by the body's cooling mechanisms when trying to maintain thermal equilibrium, an individual's vigilance and senses remain more acute. Individuals can focus more clearly on the task at hand, not being physiologically and psychologically distracted by the uncomfortable reactions their body is experiencing as a result of trying to attain or main-tain thermal equilibrium. According to Dr. John LoZito, Neurologist, utilizing the optimum temperature of 50-53degF of the alkane blend in these vests "...­helps maintain the body's 'vitals', the first technology I've seen to work in harmony with physiology to cool both the mind and body. I find this technology especially effective in high risk occupations where 'adrenaline stress' adds further negative pressures to the already stressed individual."

Former trainer for the Miami Dolphins, Dr. Gary Berns states, "this technology uses safe, comfortable temperatures that work in direct correlation to our body's physiological, neurological and metabolic systems. As the cool vest absorbs the excess heat from the chest cavity or extremity, the blood flow begins to cool. As the blood cools, the sympathetic system slows down the metabolism. We then vasodilate and decrease the sympathetic outflow and turn our body into a more calm, relaxed state further reducing body vitals, i.e. blood pressure and heart rate etc. Cooling the blood flow at its source with a higher temperature medium keeps the body from adversely reacting - fighting vasoconstriction by pumping more blood through the arterial system. This technology is the first that I have seen work in concert with maintaining normal body vitals."

To further substantiate the effectiveness of "optimum temperature" utilized in body cooling, the U. S. Air Force Operations Test & Evaluation Center (AFOTEC), Randolph AFB Texas in conjunction with Alamo Research Laboratory conducted an extensive 10 day evaluation of the phase change technology in the exotherm type cooling vests. This technology was studied to determine the utility of these one-of-a-kind body cooling devices for sole source inclusion in the Air Force Firefighting Equipment Tables of Allowance for procurement worldwide. Ten male professional firefighters with medical clearance for unrestricted duty from San Antonio, Texas volunteered to participate in this study. All firefighters were fully acclimated to high heat and humidity.

Laboratory testing was conducted to baseline test participants' physical condition to quantitatively evaluate the physiological benefits of wearing these constant temperature cooling vests in high heat, high exertion environments. Field testing employed task-qualified firefighters wore these cool-ing vests in realistic operational environments assessing compatibility with the firefighting mission. Firefighters were dressed in their complete pro-tective ensembles (bunker suits) including helmet, boots, gloves, face masks, hoods and self-contained breathing apparatus (SCBA). Meteorological conditions were also recorded and reported by Alamo Physiological Research Institute in a technical report depicting each subject's heat stress loads, both with and without vests.

AFOTEC RECOMMENDATIONS:
A. Add the cool vest to the firefighter's table of allowances. The exotherm type cooling vest has value and enhances mission response for operations in high-heat environments not involving first alarm firefighting as it was determined that assembling and donning the vest properly (utilizing the ice and water method) required as much as 90 seconds. To reduce the donning time, it was agreed the cool vests should be previously charged and assembled and stored in a cooling mechanism
B. Prior to inclusion of the vests into equipment tables' of allowance, publish a concept of operation. Ensure the concept of operations and tables of allowance addresses the support equipment required for charging, storage, and transportation of the exotherm type cooling vest.
C. Make the cooling vest available to all support personnel who are required to perform duty in high-heat environments. Notably, explosive ord-nance disposal, hazardous material abatement, and security force personnel could use the system to enhance mission response capabilities.

AFOTEC CONCLUSIONS:
- A 22% increase in the firefighter's work time was noted. Work time before rise in core temp. fom an average of 33.1 minutes to 40.4 min.
- No significant change in core body temperatures, blood pressure or heart rates.
- They felt the constant heat exchange rate enhanced the body cooling effects by minimizing thermal shock generally felt by the vests that use ice or gel as an exchange medium.
- Reduced recovery time for those who put the vest on after completing task.
- Test participants comfort levels, primarily influenced by the vest maintaining lower back and chest skin temperatures were rated higher.
- Slower build up of core body temperature while wearing cool vest.
- Test participant comments and survey responses indicated that they felt their recovery was enhanced when they wore the vests during and after test events.
- Participants commented the vest would be useful, provide additional comfort and enhance mission accomplishment when performing any duties in high-heat environments and during hazardous material abatement operations.