Peter Sinks, Utah

     On February 1, 1985, the temperature at Peter Sinks in Utah plummeted to 69.3  degrees below zero...the second coldest ever recorded in the lower 48 states. The lowest was 69.7 below at Roger's Pass, Montana in January of 1954. 

     Peter Sinks and nearby Middle Sink have the distinction of having all but one of the monthly low temperature records for Utah. Peter Sinks is located in the NE corner of the state and it is so cold due to a combination of the area’s unique basin topography, high elevation and dry climate. 

     Peter Sinks, at an elevation of 8,164 feet, is a natural limestone sinkhole approximately one-half mile in diameter, so it can be likened to a bowl, which has no valley outlet to drain water or air out of it. On calm cloudless nights this high basin loses accumulated day time heat to the atmosphere and the cool dense air slides down the slopes into the basin floor in a process known as cold air pooling.

 

     Extremely low temperatures can occur, especially in the wake of wintertime arctic fronts. Cold as 69 below is, it's not an unusual reading during December, January, and even February at Oymyakon in Siberia which is at the heart of the Siberian "pole of cold," site of the coldest permanent settlements on Earth. The lowest temperature on record there was reached on February 6, 1933, with a reading of 90 below. 

     What happens to a person at these extreme temperatures? Hypothermia starts setting in when a person's body temperature drops from the normal 98.6 degrees to about 95 degrees. 

     The body begins to shut down. Heart and breathing rates slow down, accompanied by confusion and sleepiness. Without rapid rewarming, your heart rate and breathing slows even further, leading to poor circulation to the brain, heart and extremities, which is fatal. 

     Hypothermia can develop in as little as five minutes in temperatures of minus 50 degrees Fahrenheit if you're not dressed properly and have exposed skin, especially the scalp, hands, fingers,and face. At 30 below zero, hypothermia can set in in about 10 minutes. 

     Hypothermia is a medical emergency when your body loses heat faster than it can produce it. As your body temperature drops, your heart, brain, and internal organs cannot function. Without aggressive resuscitation and rapid rewarming, you will ultimately not survive. 

     Oddly, stripping off clothing is a common occurrence in later stages of hypothermia. That's due to nerve damage and mental confusion... a person may feel like they're burning up rather than freezing and begin taking off their clothes and shoes. The phenomenon has a name: paradoxical undressing.