The troops mentioned above who were sent for the winter to Fairbanks were advised to "hold their breath" when going from one warm building to another, any time the temp was below -20F. The rationale was that if your lungs were full of warm (and relatively moist) air, breathing in the colder air could cause icing in the lungs and/or freezing of lung tissue.

"Intake filters" (mufflers etc) were used for longer exposures to anything cold, with the same -20 being the "warning temp" when extra cautions were advised.

At least one person came back to Yuma with a diagnosis of "frostbitten lungs" and spent some time in the YPG Hospital "under observation." So far as is known he was returned to normal duties when they were satisfied that he was "properly thawed."

John