Warning Signs of Hypothermia: Know Your “Umbles”

A series of telltale consequences begin to unfold as core temperature drops and hypothermia sets in. Knowing your “umbles” will help you recognize them—and take preventative actions before it’s too late.

The “Fumbles” 
Approximate Core Temperature: 98.6 to 95 degrees
Condition: Mild Hypothermia
One of the first signs of hypothermia is an inability to perform complex tasks with your hands. As your core temperature drops, your body responds by restricting blood flow to the extremities, which leads to cold numb hands (among other effects) and difficulty with fine motor skills. Your body will also begin shivering to generate warmth, though you can still control it voluntarily. You can still walk and talk.

The “Stumbles” and “Mumbles”
Approximate Core Temperature: 95 to 90 degrees
Condition: Moderate Hypothermia
As core temperature descends below 95 degrees, it becomes increasingly difficult to walk normally. Movements become slow and labored. Walking a straight line for more than 20 to 30 feet becomes impossible. Stumbles become increasingly common. Violent uncontrollable shivering racks the body and mental function becomes compromised. Speaking is difficult and slurred. Sluggish thinking and confusion become apparent.

The “Crumbles”
Approximate Core Temperature: 90 degrees and below
Condition: Severe Hypothermia
This is now a serious, life-threatening situation. You lose the ability to walk. Your body stops shivering in a last-ditch effort to conserve energy. Your behavior becomes extremely confused and increasingly incoherent. As your core temperature continues to drop, you slip into a semiconscious stupor, your pulse and respiratory rates decrease, and ultimately you die from cardiac and respiratory failure.

Learn more about how to avoid, recognize, and treat hypothermia.

Photo: Flickr Commons; Compass Points Media


About the Author…

Matt Heid


Equipped blogger Matt Heid is AMC's gear expert: He loves gear and he loves using it in the field. While researching several guidebooks, including AMC's Best Backpacking in New England, he has hiked thousands of miles across New England, California, and Alaska, among other wilderness destinations. He also cycles, climbs, and surfs.

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