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Hypothermia in the Gulf?

 

Hypothermia in the Gulf?

By Randy Boone

 

Because I have spent most of my U.S. Coast Guard career in cold water areas (two Antarctic, one Arctic icebreaker missions, Traverse City Michigan, and three tours in Kodiak Alaska), 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.

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 boat or 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. I learned that hypothermia (lowering of body core temperature) has an adverse effect on the human body, even in small degrees. The 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 consciousness due to hypothermia.

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 "Indefinitely" 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 approved 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 15, 2007 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 chart below and determine the annual average temperature of the area that you do most of your boating in. If you take the warmest water (EYW) and average it over 12 months, you come out with an average water temperature of 79 degrees. Water that will whisk your body heat away twenty-five times faster than air and can cause you to become unconscious and drown within 3 hours (if not wearing floatation).

 

 

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 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 Escape Lessening Position (H.E.L.P.) (below), 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 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 50 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. 

 

The Trick: 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 ambient 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.

If your sinking 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?

 As the Captain of your vessel, you are trusted to make the right decisions to protect you and your passengers should the unfortunate 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. Your lifevests, and especially your children's lifevests, should be on and snugged up tight, just like you want it to feel while in the water. 

The purpose of this writing is to educate all overwater travelers that there is a certain risk involved that I believe boaters need to know about. The word is out there pretty good up North. They have a better understanding of how dangerous hypothermia is, and because of this, most have prepared by placing a liferaft in the boat, wearing their lifevests, and carry a grab bag and so on, but what about the individuals in the "warm" blue waters of the Gulf of Mexico? Does the terminology warm water trick you into believing that you can just tread water without floatation until someone notices you're missing and initiates a search for you? Yes, if the water is above 75 degrees you will be able to stay out there a little longer but to tread a overnight stay may be too long, depending on your age, body mass, and endurance.

  

 

By maintaining the H.E.L.P. or Huddle position, you can extend your survival time by several hours.

This procedure CANNOT be performed without flotation.