When the body faces a cold challenge that is prolonged or very sudden and intense, and it can no longer maintain the core temperature. A very sudden mechanism would be falling through the ice into the lake and is considered to be “acute” mild hypothermia. Mild hypothermia from a prolonged challenge is generally caused by cold exposure over several days and inadequate nutrition–it is from depletion–and we label it “subacute” mild hypothermia.
Shivering is the body’s mechanism to rapidly generate heat–remember movement equals heat. But we need fuel to shiver, so you need to make sure the patient is being fed and hydrated.
Staying hydrated and fueled and being able to retain the heat we produce are the best preventative measures. Staying hydrated and fueled will also help with acute hypothermia as the patient will have more fuel for resiliency and to help with recovery.
Mild Hypothermia exists when we lose heat faster than we can produce it and the core temperature of the body drops below 96 degrees F. But we don’t need a temperature to assess this.
Mild hypothermia involves shivering and can become very intense and uncontrolled. There will also be slight alterations to mental status–what we call the “umbles” (st-umbles, gr-umbles, f-umbles, and m-umbles).
Patients may also experience “cold diuresis” which is a fancy way of saying you have to pee when you get cold.
Treating mild hypothermia depends on which form it is: acute or subacute.
For both types, you need to get the patient dry, insulated, and fueled. Water draws heat 25 times faster than air of the same temperature, so any moisture or wet clothing needs to be removed and replaced with dry clothing.
We need to keep the wind off of them and add an appropriate layer of insulation.
Providing calories is essential to heat production, so food that is easily digested or absorbed is the best option. The body quickly absorbs simple sugars, so honey, oral glucose, or candy works.
Because of the cold diuresis as a result of the body shifting fluids shell to core, we also need to make sure the patient is staying hydrated.
With subacute mildly hypothermic patients, we absolutely need to get nutrition and hydration on board. Their hypothermia is a result of depletion. Because the patient is low on fuel we need to get some food on board before getting them to move around.