Hypothermia
Hypothermia is a condition
in which body temperature drops below 35°C (95°F) and certain abnormalities
in human physiology occur. Here are the most common symptoms and suggested
methods of treatment:
|
|
|
PHASE
|
SYMPTOMS
|
TREATMENT
|
|
35°C
|
“goosebumps” (pricked skin),
cold blue skin, and “second shivers” |
The
earlier the phase, the easier the recovery. Dry off in a warm place, wear
dry clothes, run and do physical exercises. |
35°C
34°C
|
low sensitivity,
convulsive contraction of muscles, yawning, slow heartbeat (12-36 beats
a minute), high blood pressure, muscle stiffness |
Drink hot coffee or tea
with much sugar, bathe in warm (but not too hot, up to 44°C) water,
place hot-water bottles near the legs and neck, tuck up in a warm bed. |
34°C
32°C
|
unsteady gait, slurred speech,
languid condition |
All of
the above and send for the doctor. |
32°C
30°C
|
disturbances
of the mind, nonsensical speech, no movements |
The patient
needs medical treatment. Obligatory techniques – vigorous and immediate
rewarming and artificial respiration. |
28°C
27°C
|
blackout, cardiopulmonary
and thermoregulatory arrest |
The table below provides
critical lengths of stay under water:
| Water t |
0°C |
10°C |
15°C |
20°C |
25°C |
|
Stay under water
without protective clothing, which results in loss of consciousness: |
| Time |
15 minutes |
15 minutes to 1 hour |
2 to 4 hours |
3 to 7 hours |
12 hours |
|
Stay under water
without protective clothing, which results in death: |
| Time |
15 to 30 minutes |
1 to 2 hours |
6 to 8 hours |
safe |
safe |
Prevention of Hypothermia
There are various diving
suits to avoid heat loss: neoprene wet suits, dry suits and specially heated
suits. Still, it is recommended to rub the body with warming ointments
before long dives. Cold divers should not dive for a second time the same
day because it is difficult to determine when body heat has reached its
normal state.
Before diving wearing a
neoprene suit, make sure that:
-
the suit is not too narrow and
does not squeeze any blood vessels
-
he suit is not too broad so
that water does not enter freely and cool the diver
-
the suit corresponds to the
depth (due to the pressure, neoprene loses its protective properties and
cannot isolate cold)
Rules to avoid overcooling:
-
do not enter cold water if you
are warmed
-
pour some water over your body
before jumping into cold water
-
be careful of cold currents
( the first dive should be done with hands stretched forward in order to
sense the thermal differences between water layers)
-
do not dive if you are frozen
-
do not dive with full stomach
-
do not stay under water if you
feel shivers
-
do not enter the water without
protective clothing if the temperature is below 16°C
In case of shipwreck in cold
waters:
-
try to find a flotation device
as soon as you can
-
wear several layers of clothing
to reduce heat loss
-
keep the head and neck above
the surface because these are one's weakest parts
-
slowly enter the water; if you
must enter quickly, pinch your nose, hold your breath, and jump
-
hug your knees if alone or huddle
together with the others to avoid hypothermia
Hyperthermia
During dive preparation,
a diver in a wet suit who has been exposed to the hot sun for a long time
might become overheated. Hyperthermia is the general name which refers
to heat-related sicknesses. The two basic forms of hyperthermia are heat
exhaustion and heat stroke.
|
SYMPTOMS
|
TREATMENT
|
| dizziness, disorientation,
headache, nausea, weakness, red or pale face, rapid pulse – up to 120 beats
per minute, frequent breathing, raised body temperature > 40–41°C,
excessive perspiration, loss of consciousness |
Divers who develop hyperthermia
should stay in a cool and shadowy place, cooled with water, provided with
access to fresh air and given liquid food. In a state of unconsciousness,
the diver should be undressed and made a cool compress on his or her neck,
chest and forehead. |
The table below provides
maximum lengths of stay in the shadow.
| Air t |
15°C |
19°C |
20
to 24°C |
25
to 29°C |
30°C |
34°C |
|
Safe stay in
the shadow, wearing a neoprene suit: |
| Time |
5 hours |
3 hours |
2 hours |
1 hour |
30 minutes |
6 minutes |
Prevention of Hyperthermia
The neoprene suit should
be put on before the dive and taken off straight after that because neoprene
limits the normal emission of heat in the air. If this is not possible,
the diver should be often cooled with water and a wet cloth. |
