FORT MCCOY, Wis. -- Big Sandy Lake on Fort McCoy's South Post was covered with several inches of ice Dec. 13, when 39 students in Cold-Weather Operations Course (CWOC) Class 19-01 began their cold-water immersion training.The training is part of the curriculum for 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."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," said CWOC instructor Joe Ernst.Instructor Bill Hamilton added, "Our students get fully immersed in the water while doing the training. Once they are in the water, they will stay in anywhere from one to three minutes but never longer than three minutes."As each student took the plunge into the icy-cold water, making sure they also went under water, their reaction was immediate."For a person to fall into water in that environment, the onset of panic generally introduces itself quickly," Ernst said. "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."The students who took part in the cold-water immersion training found it enlightening and a test of their own abilities, along with the rest of the CWOC training."The best parts about this course besides the classroom training was the training about shelters, the (cold-water immersion), and the skiing," said Staff Sgt. Bridgett Smith with the Alpha Company, 452nd Combat Support Hospital of Fort Snelling, Minn.Army ROTC Cadet Taryn Chovan associated with the 16th Psychological Operations Battalion of Fort Sheridan, Ill., said the cold-water immersion training was among her greatest accomplishments during the course and said she feels more prepared to complete field operations out in the cold."I've definitely learned how to operate in the cold," Chovan said. " I didn't think it was possible to survive overnight in the winter. Overall it was a very unique experience."Ernst said cold-water immersion will continue 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.Learn more about Fort McCoy online at https://home.army.mil/mccoy, on Facebook by searching "ftmccoy," and on Twitter by searching "usagmccoy.