NATICK, Mass. -- When Soldiers are suddenly hit with a wave of Acute Mountain Sickness while operating at high altitude, they might as well be considered casualties.

For anyone, working with nausea, fatigue and a throbbing headache is nearly impossible. Yet, the Army has never had technology to plan around the debilitating effects of mountain sickness--until now.

The U.S. Army Medical Research and Materiel Command has transitioned a mobile mission-planning tool, which was developed by U.S. Army Research Institute of Environmental Medicine researchers, directly to the field. The Altitude Readiness Management System, or ARMS, is an Android-based app that can predict how likely Soldiers are to experience mountain sickness and reduced physical performance at different altitudes and provides an acclimatization module to minimize these deficits.

"ARMS is one of the first products by USARIEM ever fielded by the MRMC to a command," Dr. Beth Beidleman, the ARMS principal investigator, said. "Two commands are now using ARMS. One of them is the U.S. Army Forces Command, or FORSCOM, under the Program Executive Office Soldier program Nett Warrior. The other user is U.S. Army Special Forces."

Along with navigating steep, rocky terrains, abrupt exposure to high altitude can negatively affect Soldiers' physical and cognitive performance, as well as overall health. Altitude exposure lowers the oxygen supply to the body's tissues for a significant amount of time. Although the body is able to adapt to lowered oxygen levels over time at altitude, abrupt exposure endangers Soldiers' health and performance to the point that they may be unable to complete their missions.

"ARMS can be used to pre-plan mountain missions," said Beidleman of USARIEM's Thermal and Mountain Medicine Division. "If you use it as a planning tool, you can reduce the amount of people who are impacted by mountain sickness by either changing the ascent altitude, time of exposure or physical activity level or using Food and Drug Administration-approved altitude medication. If the mission can be altered prior to deployment based on this easily accessible information, ARMS can successfully improve Soldier readiness."

With Android phones in hand, commanders can use the three modules in ARMS to mitigate altitude illness, reduce physical performance decrements and plan altitude acclimatization.

"The illness module predicts the percentage of people that could get sick depending on the altitude," Beidleman said. "If a commander sends 100 people to 4,000 meters, ARMS will say, 'At 4,000 meters, 80 percent of Soldiers will get sick.' Commanders can plan for extra time or people based on the fact that 80 percent of our forces may feel under the weather."

ARMS also estimates whether the altitude sickness is mild, moderate or severe. Severe altitude sickness significantly slows down a mission and could result in casualties.

The percentage of Soldiers who suffer from mountain sickness can drastically impact the time to complete a mission that involves physical activity.

"If it takes Soldiers 100 minutes at sea level to complete a physical performance task, ARMS predicts it will take them 150 minutes at a 4,300-meter altitude," Beidleman said. "This allows commanders to appropriately plan enough time to complete certain missions."

Rapidly ascending to high altitude is a recipe for mountain sickness. However, commanders can use the acclimatization module in ARMS to see how long Soldiers should adapt to a lower altitude before ascending.

"It might not be acceptable for a commander to have 80 percent of his people sick," Beidleman said. "He might re-plan his mission and say, 'Instead of going straight to 14,000 feet, we will go to 8,000 or 10,000 feet for two days first, and then we will go to 14,000 feet. Now, I can decrease my likely mountain sickness level to only 30 percent of the troops.'"

Beidleman said the data in these three modules stem from over 25 years of altitude studies performed at USARIEM and recorded in their Mountain Medicine database.

"ARMS is a state-of-the-art tool that minimizes risk and increases effectiveness for Soldiers," Beidleman said. "Nothing like this has existed before, except for the Technical Bulletin Medical 505--a book--where you would search for this information. However, TBMED 505 is not user-friendly. Using ARMS, mission planners can plug in simple numbers to find out how many Soldiers are likely to get sick, the severity of their sickness, and the increased amount of time to perform physical tasks at a variety of altitudes. ARMS also provides an acclimatization tool to mitigate these deficits with the push of a button.

"ARMS does not do anything to prevent illness, but it helps commanders plan altitude missions with appropriate expectations. The good thing about ARMS is that it puts the planning tool in Soldiers' hands. They can push a button on an app and have easy access to critical information that can prevent detrimental hypoxic events from occurring."