Staying Cool Under Fire
Written by Steve Goodman
GCT 2010 Volume: 1 Issue: 2 (August)
How to Dress to Beat the Heat in Theater.
Staying cool in the heat of battle can sometimes mean more than keeping your nerves frosty. In theaters such as Afghanistan and Iraq where desert temperatures can easily exceed 120 degrees Fahrenheit, heat can be as deadly as a sniper’s bullet.
“Heat stress first affects the way the human brain processes information and reacts to situations. Once the body begins undergoing heat stress, the brain begins to fight an internal battle for survival, which becomes the primary objective regardless of what is happening around the person, even on the battlefield,” said Dr. John S. Surie, president of Arctic Heat USA, a New Jersey-based manufacturer of wearable cooling vests for warfighters. The doctor continued, “The human body begins to try and conserve energy in hopes of survival, which takes away from his or her ability to stay on task. Performance levels drop, mental acuity declines and the person begins to react much slower to external stimuli—all of which can mean life or death to the warfighter.”
In fact, between the jungles of Vietnam and the deserts of Iraq and Afghanistan, there have been engagements by ground combat troops where heat stroke and heat exhaustion were responsible for more casualties than enemy fire. The development of personal cooling technologies is trying to change all that.
Personal cooling garments have been around for quite some time. Of course, developing and deploying them for the military has its own set of challenges. “Coming up with an appropriate cooling garment for the military presents a threefold problem as we see it,” said Surie. “One, recharging the vests; two incorporating the vests into the warfighter’s current uniform requirements; and three, how and when to use the vests. Arctic Heat USA has a developed a number of solutions for recharging vests for additional use. We work closely with the purchaser, and we have found that educating the user or coordinator for the particular military unit where it will be deployed about how the vest works and how to use it properly offers the best results for issues two and three.”
Arctic Heat’s cooling vests and cooling caps are currently deployed around DoD facilities in Nevada and Arizona, and they are being used by units in both Afghanistan and Iraq as well as by the Australian military in Iraq.
Basically, there have been two different approaches to the development of wearable cooling garments to deal with the problem of heat stress on ground troops in hot environments. The first method is to use consumables, such as the use of ice or other phase change materials in vests and other garments, such as those made by Arctic Heat, Polar Products, Texas Cool Vests and several others. They work by lowering core temperature through direct body contact.
“The cooling vest has been shown to lower the skin temperature by up to 63 degrees Fahrenheit, and when used over light clothing, up to 54 degrees Fahrenheit,” said Surie.
Another way to add additional wearable cooling under a uniform or body armor, with or without a consumable type cooling vest, is to wear undergarments that are specially designed to wick away moisture.
“We can cool down a soldier by wicking the moisture away from their body and dissipating the moisture so that they stay drier and cooler,” said Sherry Lyons, director global business development, government and ilitary, with North Carolina-based XGO. “It is hard to measure in terms of degrees how much cooler, but what we do is measure the wicking capability. Mixed with the breathability of our fabric, our Acclimate Dry fabrics wick moisture at a rate of 3 inches in 3 minutes.”
XGO provides Acclimate undergarments to the U.S. Army, and they are being used effectively in Iraq and Afghanistan.
Wicking fabrics and cooling vests are proving effective in making ground troops more comfortable in harsh environments, and in preventing the devastating effects of heat stress. However, such rechargeable cooling vests can only be so effective on the battlefield, especially in Operation Iraqi Freedom, where temperatures in excess of 130 degrees Fahrenheit have been reported. Even Surie admitted, “Many times, cooling vests are not able to be used while in battle, but they are easily employed prior to, or can be used effectively in the recovery process after prolonged exposure to heat.”
The other approach involves what are known as a microclimate cooling garments (MCG) or microclimate cooling systems (MCS). Rather than relying on consumable chemicals that need to be recharged for cooling, MCGs are powered so that they can be used continuously.
MICROCLIMATE
Despite what it sounds like, a microclimate is not something you will hear the local meteorologist discussing on the evening news. A microclimate is a small self-contained zone within a larger climate with a very different set of conditions.
The idea behind microclimate garments is to create a cooler environment in the area just surrounding the foot soldier, despite how hot it may actually be in the theater of engagement around him. Microclimate technology has been used by DoD in vehicles, on airships, in shelters—and is now in development for ground troops “Qinetiq North America has been involved in microclimate cooling technologies since the early 1980s for both vehicle and man-portable applications,” said Daniel L. Fischbach, director integrated human systems, QinetiQ North America Technology Solutions Group. “Our original focus was to develop portable systems that could be used by independently mobile individuals, including ground soldiers. We had a number of programs to develop the key technologies in the mid-tolate ’90s with portable applications in mind.”
Those research and development efforts led directly to the development of the MCS that is supplied as part of U.S. Army Air Warrior Program. “Air Warrior started in 2000; the objective was to enable U.S. Army helicopter aircrews with the ability to fly in a chem-bio environment with protective clothing. Under these conditions, their mission duration objective could only be met by using microclimate cooling to keep body core temperature under control,” said Fischbach.
The manufacture of that product known as The Chiller began in 2003. In an aircraft equipped with a Chiller MCS, helicopter crews wearing chemical biohazard protection gear can safely endure a mission lasting up to almost six hours, as compared to about 1.5 hours without the system. The MCG is a vest worn as an undergarment. It is connected to a condenser unit, which chills water and Integrated microclimate cooling system in testing. [Photo courtesy of U.S. Army] pumps it through small tubes embedded in the vest.
Qinetiq is developing elements of this technology to adapt for ground soldier use, but the challenge with man-portable is twofold: weight and portability. Said Fischbach, “We designed a completely different high speed compressor to meet these challenges. Our latest product, the Integrated Microclimate Cooling Unit, has been produced in prototype version, was certified for field use, and is being evaluated by the government at this time.” Those tests and that prototype were developed in conjunction with U.S. Army Soldier Systems Center (NSSC) in Natick, Mass.
The units were first tested in 2009 at the Maneuver Battle Lab at Fort Benning, Ga. Those units as tested weigh about 4 pounds each; the goal is to get them down to less than 3 pounds by 2015. The cooling unit itself can be mounted to any Modular Lightweight Loadcarrying Equipment area on the soldiers’ body armor or rucksacks. Like the Air Warrior MCS, the system chills water and pumps it through tubing integrated into the soldier’s combat shirt.
While still experimental for the individual soldier, the system has been adapted for, and is deployed with, several U.S. Army ground vehicles. According to Fischbach, “It is currently being used by the U.S. Army Stryker and Bradley fighting vehicles, the USMC M1A1 Abrams, USMC M88 tank recovery vehicle, and U.S. Army M9 armored combat earthmover. Over 18,000 cooling units have been manufactured and delivered.”
BEAT THE HEAT
According to the Army Office of the Surgeon General, there are as many as 2,000 cases of heat-related incidents each year, and as many as 1,500 soldiers actually diagnosed with heat exhaustion. There were 258 cases of heat stroke and six deaths because of heat exposure, and that is just the reported statistics.
The actual impact of the way heat affects critical performance, and how that negatively influences the outcome of a mission is much harder to evaluate, but certainly it is a factor. Said Surie, “Heat can severely affect soldiers fighting in these climates as their bodies are not fully acclimated to living in such conditions. Even people who live in these conditions have a difficult time performing in those extreme temperatures.”
“Before Air Warrior, cooling was considered a ‘nice to have’ product for our warfighters,” added Fischbach. “However, the Army felt it necessary to develop the technology for operations in their toughest environments. When our forces became engaged in Iraq and began experiencing the exceptionally high temperatures during the Iraqi summer, microclimate cooling became a much more necessary item.”
It is not just the health and performance of individual ground fighters that is at stake here. In these brutally hot environments, wearable-cooling technologies can be seen as a force multiplier, since troops will be able to perform mission critical operations longer, and with less need for breaks for rehydration and recuperation.
The thousands of ground combat troops deployed in Iraq not only have to deal with these extreme conditions; they have to do it wearing a full military uniform, body armor and other equipment. Those who have been using the various cooling vests and wicking undergarments that are available report that these products have made a significant difference in beating the heat.
THE COLD TRUTH
To be an effective fighting force, our ground troops need to be able to give their very best in any environment under any conditions in the world.
For the most part, over the past few decades American military personnel have had to fight in sweltering jungles and uncompromisingly hot deserts, exposing them to temperature extremes that test the very level of human endurance. There can be no doubt for the need to continue to develop new climate control technologies for the individual soldier. And while the prototypes developed by NSSC show a lot of promise, many challenges remain. “Current trends for ground soldiers, through the Future Soldier Initiative as well as other programs, is to ‘lighten the load,’ so it is unlikely that the body-worn cooling at its current state of development will be broadly accepted,” said Fischbach.
“However, thermal management for ground soldiers remains a huge issue. Major breakthroughs will be required to significantly reduce the size and power consumption of body-worn systems; likewise, great leaps in battery technology are also needed to reduce the amount of weight that needs to be carried to run these systems.”
So until practical MCGs for ground troops can be widely deployed, passive cooling systems are the order of the day. While ice filled cooling vests and water wicking underwear may not be the sexiest military technology out there, they are real cool ways to help our warfighters complete their missions. ♦