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Hypothermia in the Gulf?

 

Because I have spent most of my U.S. Coast Guard career in cold water areas, I have gained a tremendous respect for the sea and have learned that most offshore drownings are connected in some way or another to hypothermia. I have also learned that you do not have to be in "cold water" areas to succumb to hypothermia. For the purposes of this writing, I will refer to cold water as any water temperature that will lower the human body temperature below 98.6 degrees. Because the Gulf of Mexico is considered warm waters by most, it is that idealogy that makes it so dangerous. Yes, the water is much warmer than Alaskan waters, but the human body reacts the same way to 58-60 degree water as it does to 45 degree water. You will first encounter a cold water shock which will cause you to start gasping while somehow shouting some expletives between the gasps, you will ball up in an attempt to stay warm. You will shiver uncontrollably, your fingers and feet will start losing mobility, and without floatation, you will not be able to keep your head above the waterline. If you live past this point, then you will have to deal with the continual body shut-down effects of hypothermia.

 

Cold water immersion is survivable if you take the proper steps. If you look at my “Seven Steps to Survival” page you will see that Recognition is the first step. If you fail to recognize that a ditching is  possible, as some do, and if you fail to place floatation (life-vests and life-raft) in your aircraft, you will likely be one of the many sad statistics stating, “The occupants were not wearing floatation devices”.

While in the U.S. Coast Guard stationed in Kodiak Alaska, I had the privilege of serving with Dr. Martin Neimeroff (Captain). Dr. Neimeroff was the Coast Guard’s leading expert for cold-water immersion. Through his teachings, I learned that hypothermia (lowering of body core temperature) has an adverse effect on the human body, even in small degrees. This human machine was designed to operate at a constant 98.6 degrees, and any variation up or down causes ill effect (hyperthermia/hypothermia).

The human body generates a small amount of heat through shivering (Stage One Hypothermia  98.6 F to 95.0 degrees). Feeling Cold, Shivering, Drowsiness, Slurred Speech, and Disorientation are all symptoms of stage one (mild hypothermia). Note: A person with “Stage One” hypothermia will appear to be intoxicated.

As you can see, a variation of only 3.6 degrees from your normal body temperature can cause adverse effects that can severely affect your ability to do the things you need to do to survive.

 

Now lets go a step further. Lets say your body temperature drops below 95 degrees. You are now entering Stage Two Hypothermia (95-91 degrees). The symptoms include diminished shivering, decreased level of consciousness, and slower rate of respiration. For the person in water (P.I.W.) without floatation, this is where you are starting to get into very serious trouble. The shivering you experienced in stage one hypothermia has caused you to use up a lot of energy. Once the shivering stops, your body will no longer have the ability to re-heat itself. You will be very exhausted and unable to maneuver from on coming waves and swells. You will start gasping in mouthfuls of water and will not be able to stay afloat, thus drowning will eventually occur. 

Now move down to the next level. Stage Three (Severe Hypothermia) 91-86 degrees. Symptoms include muscle rigidity, and loss of consciousness. I hope I don’t have to explain what happens to a P.I.W. without floatation when he loses consciousness.

In the hypothermia chart below, you can see the estimated survival time in water. This will vary from person to person and a lot has to do with body mass. For instance, a child would be quicker to succumb than a man. The thicker the body mass, the longer the survival time.

 

The likelihood of dying from hypothermia is slim for a PIW without floatation. His cause of death would most likely read; Drowning due to the inability to keep his head out of the water. He drowned, but the drowning was the result of losing control of his arms and legs or losing consciousness due to cold water immersion.

 

Even though the chart shows the EXPECTED TIME OF SURVIVAL for a person in 75 degrees water to be from 3 hours to Indefinitely, the "Indifinitely" wording is based upon the condition that you are wearing a lifevest and are able to keep your head out of the water even in the event of unconsciousness (as all CG apporved lifevests are designed to do).

 

HYPOTHERMIA CHART

IF THE WATER TEMPERATURE (F) IS:

EXHAUSTION OR UNCONSCIOUSNESS

EXPECTED TIME OF SURVIVAL IS:

32.5

Under 15 Minutes

Under 15 - 45 Minutes

32.5 - 40.0

15 - 30 Minutes

30 - 90 Minutes

40.0 - 50.0

30 - 60 Minutes

1 - 3 Hours

50.0 - 60.0

1 -2 Hours

1 - 6 Hours

60.0 - 70.0

2 - 7 Hours

2 - 40 Hours

70.0 - 80.0

3 - 12 Hours

3 Hours - Indefinitely

OVER 80.0

Indefinitely

Indefinitely

 

The water temperature in the Eastern Gulf of Mexico today (April) is averaging around 75 degrees. If you look at the hypothermia chart above, you will see that you could become unconscious within three hours! Now look at the months November through March and you can see water temperatures that give you even less time to survive. This is why it is so very important that you get out of that "heat robbing" water.

 

 

Location

Present
Temperatures

JAN

FEB

MAR

APR

MAY

JUN

JUL

AUG

SEP

OCT

NOV

DEC

Key West FL(MLRF1)

78.3

69

70

75

78

82

85

87

87

86

82

76

72

Naples FL

78.3

66

66

71

77

82

86

87

87

86

81

73

68

St. Petersburg FL

N/A

62

64

68

74

80

84

86

86

84

78

70

64

Cedar Key FL(CDRF1)

N/A

58

60

66

73

80

84

86

86

83

76

66

60

Pensacola FL

69.4

56

58

63

71

78

84

85

86

82

74

65

58

Dauphin Island AL(DPIA1)

N/A

51

53

60

70

75

82

84

84

80

72

62

56

Grand Isle LA(GDIL1)

N/A

61

61

64

70

77

83

85

85

83

77

70

65

Eugene Island LA

N/A

51

53

60

68

76

83

85

85

82

74

63

55

The major heat loss areas are the head, neck, underarms, sides of chest, and groin. When you submerse your body in water, you immediately start losing heat in these areas through: Convection (the movement of water), and Conduction (skin touching anything cooler than the body temperature).

 

Conduction from water submersion occurs twenty-five times faster than air!

 

By assuming the Heat Loss Lessening Position (H.E.L.P.), (left), you can protect the vulnerable heat loss areas of your body (head, neck, underarms, sides and groin).

Please take note that this position can only be maintained with the help of a floatation device. Without the floatation, you would have to straighten your legs and kick, exposing your groin area, and move your arms outward to steady yourself, exposing your neck, underarms, and sides. By maintaining the H.E.L.P. position (left pic) you can extend your survival time by several hours.

I am often asked about life-rafts. Are they necessary in the Caribbean waters? I say absolutely!

By removing your body from the water, you increase your chances of survival by over 70 percent! 

By getting into a canopied liferaft you not only get out of that heat robbing water, you can also protect yourself from wind and rain. 

Side Note: Everyone knows that when you get out of a swimming pool you will immediately start shivering and this shivering is quickly resolved by jumping back into the "warm" pool water. The trick is this, movement of ambiant air moving across your wet skin will trigger nerve sensors on the outer layers of the skin. These sensors tell your brain, "Hey it's cold"! When you jump back into the water, you immediately feel warm again because the skin had previously acclimated to the temperature of the water. Even though the water temperature may feel warmer to these skin sensors, it is robbing heat from the inner core area of your body (the area that surrounds your heart) at a rate of twenty five times faster than the ambiant air.

If your ditching occurs late in the day, you stand a good chance of an overnight stay. That’s 8-10 hours! A life-raft can be your best friend in this situation. By climbing into a liferaft, you have increased your survival time by getting out of the water, you have increased your target size, and you should now have some signaling equipment that may facilitate in your being found.  Even on land, the liferaft will provide the same features. Why would you not carry a liferaft?

Flying over water is no different from flying over land. As a pilot, you are trusted to make the right decisions to protect you and your passengers should the unfortunante event happen. Don't let your ego, a few extra dollars, and a few extra pounds, stand in the way of ensuring the ultimate safety for you and your family. Don your life-vest prior to climbing into the cockpit and carry (within reach), a life-raft.

Don't just brief egress procedures, practice them. Does your liferaft and ditch kit fit out of all the exits?

 

Randy Boone

 

 

Huddle Position (can only be accomplished with floatation). Place injured persons or children in center.