Prior to the onset of hypothermia the body maintains a relatively stable temperature whereby heat production is balanced by heat loss. When the outside environment gets too cold or the body's heat production decreases, hypothermia occurs (hypo=less + thermia=temperature).
The main symptom of poison oak, ivy, or sumac is an intensely itchy, red rash. ... However, you should contact a doctor right away if you are highly sensitive or have the following symptoms: Swelling of the face or throat; Rash on the genitals; ...
About 15 percent of the 120 million Americans who are allergic to poison oak, poison ivy, and poison sumac are so highly sensitive that they break out in a rash and begin to swell in 4 to 12 hours instead of the normal 24 to 48. Their eyes may swell shut and blisters may erupt on their skin.