“
MILD HYPOTHERMIA
Mild hypothermia has been termed by some experts as “a case of the umbles”: the patient typically first stumbles, then fumbles, grumbles, and later, mumbles. As gross motor skills are affected a stumbling gait begins. Fine motor skills decrease and give rise to fumbling. The patient begins to draw inward, becoming less and less sociable. Designed to function optimally at approximately 98.6 degrees F (37 degrees C), the brain will begin to malfunction when its temperature drops below the ideal. In the case of hypothermia, normal thought processes become impaired. Mild hypothermia could be termed “mild stupidity.” Patients begin to make poor decisions, such as not putting on rain gear when rain begins to fall. Patients typically show increasing confusion and apathy. Fine shivering, relatively controllable by the patient, begins. A healthy sign, shivering is the body’s involuntary form of exercise to increase core heat. But mild hypothermia is insidious, affecting the ability of the patient to think, to be aware of its onset, to take care of self.
When the brain first senses heat loss is gaining on heat production, it stimulates the primary defense mechanism against further heat loss—vasoconstriction of the peripheral circulation (shrinking of the blood vessels in the skin). This vasoconstriction dramatically slows blood flow to the surface of the skin, where it will lose heat into the surrounding environment. The lack of blood causes the skin to become pale and cool. BMR will increase in response to the threat of cold, with an accompanying increase in heart rate and respiratory rate.
”
”
Buck Tilton (Wilderness First Responder: How to Recognize, Treat, and Prevent Emergencies in the Backcountry)