By mid-January, hundreds of Marines and Soldiers had participated in cold-water immersion training at Big Sandy Lake on Fort McCoy's South Post.The training is part of the curriculum for Fort McCoy's Cold-Weather Operations Course, or CWOC. A large hole is cut in the ice at the lake by CWOC staff, then a safe and planned regimen is followed to allow each participant to jump into the icy water. Emergency response personnel are also nearby in case they're needed."Our students get fully immersed in the water while doing the training," said CWOC instructor Bill Hamilton. "Once they are in the water, they will stay in anywhere from one to three minutes but never longer than three minutes."Joe Ernst, also a CWOC instructor, said cold-water immersion is critical to the ability to survive and operate in a cold-weather environment."The experience of a service member being introduced to water in an extreme-cold environment is a crucial task for waterborne operations and confidence building," Ernst said. "For a person to fall into water in that environment, the onset of panic generally introduces itself quickly. For our service members who will be operating in an extreme-cold environment, it is a task that, if not trained for, can produce unnecessary casualties."The human body's reaction to falling through ice and into frigid water starts with the mind, Ernst said."The shock to the system generally results in an immediate response of a heightened rate of breathing," Ernst said. "Visual limitations (tunnel effect), confusion, and muscle tension are common reactions. The ability of a person to regain control and composure after getting in this situation is possible."During CWOC, Ernst said the experience and guidance of the course's cadre are critical to direct students to a slower rate of breathing and advise students on regaining physical and mental control."Assessing the environment and situation will only serve as a life-saving technique," he said.Ernst said the most important aspect of training is the techniques of extraction and recovery from the cold water."Quickly building a fire, should a heated structure or vehicle not be available, is one skill set we teach," Ernst said. "We also teach the medical training that covers the effects of cold-water immersion and the timelines of recovery to prevent further injury."Many students who took part in the cold-water immersion training found it enlightening and a test of their own abilities.Staff Sgt. Joshua Dixon with Marine Air Control Squadron 2 of Marine Corps Air Station (MCAS) New River, N.C., was a student in CWOC Class 18-01 in December. He said every part of the course improved his cold-weather survival skills."The best parts of (CWOC) are all of the practical application and hands-on training you go through, especially the cold-water immersion," Dixon said. "I now have more confidence in my equipment, and I know that I am more than capable of going out into the wilderness on my own and being able to survive."For 1st Lt. Conor Nelson with Marine Air Support Squadron 1 at MCAS Cherry Point, N.C., the 'hands-on' cold-weather training, including cold-water immersion, was among the best phases."Being outside in the field is where real learning and training occurs," Nelson said. "It's one thing to watch a video and review a PowerPoint slide on survival in the cold, but it's not until you have to build a fire, construct a shelter, and fight to exist and survive in single-digit temperatures do you truly understand and grasp the concepts and importance of those lessons."Ernst said cold-water immersion will be a mainstay in CWOC for the foreseeable future as it has proven to consistently provide value."Service members who serve in units with continental and regional responsibilities that fall under the Arctic and sub-Arctic zones and who receive this training will serve as a force multiplier and invaluable asset to our commanders in the field in a cold-weather environment," he said.In addition to cold-water immersion, CWOC students are trained on a variety of cold-weather subjects, including snowshoe training and how to use ahkio sleds and other gear. Training also focuses on terrain and weather analysis, risk management, cold-weather clothing, developing winter fighting positions in the field, camouflage and concealment, and numerous other areas that are important to know in order to survive and operate in a cold-weather environment.The training is coordinated through the Directorate of Plans, Training, Mobilization and Security at Fort McCoy.Fort McCoy has supported America's armed forces since 1909. The post's varied terrain, state-of-the-art ranges, new as well as renovated facilities, and extensive support infrastructure combine to provide military personnel with an environment in which to develop and sustain the skills necessary for mission success.Today, Fort McCoy has become the Army's premier Total Force Training Center for Army Early Response Force early deployers to meet the Army's operational demand requirements. 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