IDENTIFY IMMERSION SYNDROME
Immersion syndrome is a term that covers several very similar cold injuries.
These injuries include trench foot, immersion foot, and immersion hand. Trench foot is
caused by exposing the foot to wet conditions in cool or cold weather (50F to 32F) for
an extended period of time (usually over 12 hours, depending upon other conditions).
Immersion foot is usually caused by the foot being kept in cool or cold water (usually
below 50F) for an extended period of time (usually over 12 hours). Immersion hand is
caused by the hand being exposed to the same conditions that create immersion foot.
Immersion syndrome cold injuries usually occur in three phases--the anesthetic phase,
the reactive hyperemic phase, and the vasospastic phase.
a. Anesthetic Phase. In the anesthetic phase, there is a loss of feeling
including the loss of pain in the affected part. This loss of feeling can be tested by
gently pinching or pricking the affected part and surrounding parts. The casualty will
feel the pinching or pricking in the unaffected areas, but not in the affected area. The
area may feel numb to the casualty without testing and will be cold to the touch. The
casualty will usually have a weak pulse, also. In immersion foot, the bottom of the foot
may be wrinkled and white.
b. Reactive Hyperemic Phase. In the reactive hyperemic phase, the blood flow
that was restricted in the anesthetic phase increases until the affected part is engorged
with blood (hyperemic). The affected area will be red and the limb will probably feel
very hot. The flow of blood may cause the casualty to experience "shooting" pains in
c. Vasospastic Phase. In the vasospastic phase, the blood vessels contract.
Initially, this contraction will cause the skin to look pale. This paleness is then replaced
by a bluish discoloration (cyanosis) caused by a lack of oxygen in the affected tissue.
The casualty's pulse rate will also decrease during this phase. Blisters, redness, and
hemorrhages may also develop. Gangrene (tissue death) may also occur.
TREAT IMMERSION SYNDROME
The treatment outlined below should be begun as soon as possible after noticing
the signs of immersion syndrome.
a. Dry Affected Area. Dry the affected area immediately.
b. Rewarm Affected Area. Rewarm the affected part gradually. If possible,
rewarm the part by exposing it to warm air. If warm air from a heated source is not
available, the affected area is normally rewarmed using the same procedures given for
chilblain (paragraph 5-4a). Covering the affected part of the limb with dry, loose
clothing or with several layers of warm coverings is also an acceptable method of