MA-1 becomes USELESS when under 6-7 C
You need this one....
N-3B
In 1945, the U.S. Army Air Force issued the Jacket, Aircrew, Heavy, Type N-3, the first of a long line of very successful N-3 style parkas. The N-3 evolved into the N-3B by 1958, described as "for aircrew members in extremely cold environments." The N-3B was a single breasted, four pocket, 3/4 length parka with an outer layer of nylon twill (typically sage green), insulated with a layer of wool pile fabric and lined with nylon cloth. The integrated parka hood was fur-trimmed, mouton lined. The N-3B is also known as a "Snorkel Parka" because the hood can be zipped up, leaving only a small opening (the snorkel) for looking out.