At International Falls, Minnesota the wind chill registered more than 60 degrees below zero Fahrenheit, that's less than 10 degrees away from an all time record.
At such times he would shake off sleep and creep through the chill to the flap of the tent, where he would stand and listen to the sound of his master's breathing.
He succeeded (in his own words, " excellently well" ), but in so doing unfortunately caught a chill that would, several days later, be the death of him.
Their research tells us that whenever the thermometer drops below 50 degrees Fahrenheit and the wind blows by at least three miles per hour, wind chill begins.