I 



Chronic, or long-onset hypother- 

 mia, occurs for exposures greater 

 than 1 2 hours and can develop over 

 several days. It usually happens to 

 people who work in temperatures 

 below 50 F. They become wet from 

 precipitation, perspiration or sea 

 spray. Victims of chronic hypother- 

 mia may experience "silent hypother- 

 mia," in which the gradual onset of 

 cold produces physical and mental 



fatigue unaccompanied by shivering 

 or other indications of cold. 



Symptoms 



In most cases, mildly hypother- 

 mic individuals shiver. In the early 

 stages, vigorous shivering is usually 

 accompanied by increased pulse and 

 breathing rates. Cold, pale hands and 

 feet (as the blood vessels in the skin 

 constrict) are the first signs of blood 



being shunted away from the 

 body's extremities. 



As the condition progresses, 

 the victim will stop shivering, 

 become confused and exhibit poor 

 coordination, speaking difficulty, 

 disorientation and poor judgment. 

 These symptoms usually occur 

 when the body core temperature 

 slips below 90 F. At this point, 



Continued 



COASTWATCH 1 7 



