PCL 1- signs and symptoms of hypothermia

Signs and symptoms of hypothermia

Mild hypothermia (32–35C body temperature)

1. Shivering

2. Intense discomfort

3. Feeling cold

4. Low energy

5. Diuresis

6. Tachycardia (rapid heart rate)

Moderate cases (28-32C)

The symptoms of moderate hypothermia include:

1. violent, uncontrollable shivering

2. pale skin

3. being unable to think or pay attention, lost of concentration

4. confusion / delirium (sudden state of severe confusion, rapid changes in brain function, sometimes associated with hallucinations & hyperactivity) -*

5. loss of judgement and reasoning, (try to remove warm clothes)- cold-induced malfunction of the hypothalamus / muscles contracting peripheral blood vessels become exhausted (known as a loss of vasomotor tone) and relax, leading to a sudden surge of blood (and heat) to the extremities, fooling the person into feeling overheated

6. difficulty moving around or stumbling (weakness)

7. feeling afraid

8. memory loss

9. fumbling hands and loss of coordination

10. drowsiness

11. dysarthria (impaired articulatory ability from defects in peripheral motor nerves eg. slurred speech) - *

13. slow, shallow breathing and a weak pulse. (Once the brain cools to around 30C, the structure that regulates body temperature (hypothalamus) stops workin.breathing slows and the lack of oxygen to the heart causes it to beat inefficiently. This is known as ventricular fibrillation. disorganized rhythm in which the heart is unable to pump, may occur at core temperatures below (28c) This is one type of cardiac arrest. The heart can no longer pump blood and the body is starved of oxygen. Can be fatal without proper treatment.

12. bradycardia (weak pulse) - decreased spontaneous depolarization of the pacemaker cells

Severe cases <22c



1. ventricular fibrillation (a disorganized rhythm in which the heart is unable to pump)

- due to sudden change in parameters i.e. myocardial temperature, changes in biochemical or acid-base status

- eg. small temperature differentials between myocardium and endocardium → dispersion of the action potential duration, refractory period and conduction speed (significantly lengthened in hypothermia) → increased vulnerability to arrhythmias

* loss of control of motor movement esp of hands, feet, and limbs,
* uncontrollable shivering that suddenly stops,
* unconsciousness*
* shallow or no breathing,
* weak, irregular or no pulse
* stiff muscles, and
* dilated pupils *

· Coma (the body’s temperature falls below 32C)*

· Death (Often the affected person will lie down, fall asleep, and die. In some cases, the patient will paradoxically remove their clothes just before this occurs)



*- loss of cerebrovascular autoregulation at about 25 °C
- reduction in cerebral blood flow by 6–7% per 1 °C drop in temperature

- markedly reduced metabolic rate → hence a considerably increased cerebral ischaemic
tolerance

- temperatures < 20 °C, ischaemic tolerance is ten times the normothermic
- EEG becomes flat at below about 20 °C