Wilderness Medical Society snowmass 2005 Page 299
Evaluation and Treatment of Hypothermia, Colin K. Grissom, M.D.
page 3
Table 2. Characteristics of mild, moderate, and severe hypothermia (adapted from
(Danzl 2001)).
Stage
Core Temperature
Characteristics
Mild
37.6
°C
37
36
35
34
33
99.6+1
°F
98.6+1
96.8
95
93.2
91.4
Normal rectal temperature
Normal oral temperature
Increase in metabolic rate and blood pressure
Maximum shivering thermogenesis
Amnesia, dysarthria, and poor judgment; normal blood
pressure; maximum respiratory stimulation
Ataxia and apathy; depression of cerebral metabolism; cold
diuresis
Stage
Core Temperature
Characteristics
Moderate
32
°C
31
30
29
28
89.6
°F
87.8
86.0
85.2
82.4
Stupor, 25% decrease in oxygen consumption
Extinguished shivering thermogenesis
Atrial fibrillation and other arrhythmias develop;
poikilothermia; pulse and cardiac output two thirds of
normal; insulin ineffective
Progressive decrease in level of consciousness, pulse, and
respiration; pupils dilated
Decreased ventricular fibrillation threshold; 50% decrease in
oxygen consumption and pulse; hypoventilation
Stage
Core Temperature
Characteristics
Severe
27
°C
26
25
24
23
22
20
19
18
15
13.7
80.6
°F
78.8
77.0
75.2
73.4
71.6
68.0
66.2
64.4
59.2
56.8
Loss of reflexes and voluntary motion
Major acid-base disturbances; no reflexes or response to pain
Cerebral blood flow one-third of normal; cardiac output 45%
of normal
Significant hypotension and bradycardia
No corneal or oculocephalic reflexes; areflexia
Maximum risk of ventricular fibrillation; 75%
decrease in oxygen consumption
Pulse 20% of normal
Flat EEG
Asystole
Lowest infant accidental hypothermia survival
Lowest adult accidental hypothermia survival(Gilbert 2000)
