Dangers of diving in cold water?

[Esox69LB]

I am a "hard headed" wetsuit diver hanging with the dry suit crowd. Living in central Illinois I have logged 39deg bottom temp in April the past few years. Aside from cramping in my legs and cold feet I am concerned about any real dangers...
Wife always said I have a cold heart, can I chill my blood or "cramp" my main muscle?
In addition to possible heart attack, what symtoms would be beginning hypothermia?
I am a 52 year old diver in good health. Not looking for opinions, but facts from folks I can trust more then my GP doc that know more about diving related dangers.

 

[do it easy]

Off the top of my head, some of the symptoms of hypothermia are confusion, shivering, numbness, clumsiness, and impaired judgement.

I'm not a doctor, but I have heard of people walking out of freezing water and onto a warm boat, seemingly safe and alive. The unforturtunate thing is that they all died as soon as they were warmed up because the cold blood from their limbs flowed into their core.

Cold water is nothing to sneeze at.

 

[TSandM]

THIS article has a nice table of symptoms.

THIS one has a nice discussion of the physiology of hypothermia.

HERE's another nice one.

But to answer your original question, if your core temperature drops far enough, it puts you at risk for abnormal heart rhythms, which can be difficult to impossible to correct without rewarming the patient.

 

[KOMPRESSOR]

I'm not a doctor... First sign of cooling is of course muscle shivering. The "dangers" starts already here, really. Since you may/may not be able to operate your equipement properly, so any "situation" may, and generally will, excalate to the worse. Now say nothing happens and you still stay down even if your brain shouts "get the h... out of this bloody cold environment". Then you've already shown a lack of judgement, which may also be a result of hypothermia that can put you in anger. I wouldn't even worry about a heart attack. Statistically there are lots of things that will happen to you many times over if you're cold, long before you'll have a heart attack!

Opinion: If I catch you diving regularly in 39F in a wet suit I'll likely kick your butt!

 

[do it easy]

I found this about "afterdrop"

Afterdrop
Is a situation in which the core temperature actually decreases during rewarming. This is caused by peripheral vessels in the arms and legs dilating if they are rewarmed. This dilation sends this very cold, stagnate blood from the periphery to the core further decreasing core temperature which can lead to death. In addition, this blood also is very acetic which may lead to cardiac arrythmias and death. Afterdrop can best be avoided by not rewarming the periphery. Rewarm the core only! Do not expose a severely hypothermic victim to extremes
of heat.

from Rick Curtis, Director, Outdoor Action Program klink on the link

 

[ianr33]

Being cold and not having good circulation can mess up offgassing which makes getting bent more likely. If you are doing dives anywhere near NDL's I would be concerned about that.

 

[KOMPRESSOR]

Being cold and not having good circulation can mess up offgassing which makes getting bent more likely. If you are doing dives anywhere near NDL's I would be concerned about that.

Very true indeed. When we do near-deco or deco, #2 rule is longer stops if you're cold! And it doesn't get "better" than that, so stay warm is #1 rule...

 

[Esox69LB]

Sounds like I need to take advantage of my DAN membership and follow up on this. I am heading to Playa del Carmen in May and will be wanting to dive sooner. More facts appriciated...

 

[D_B]

Alluding in part to what Kompressor's already said .. I know that when I get cold, my distraction factor goes way up ...

Not a medical opinion, but something I've noticed when I get cold

 

[Esox69LB]

Hey Kompressor,
Saw you want to kick my butt, Also saw you live in Norway and know your stuff about cold water. Here is another reason you may want to kick me. In my younger days I was in Copenhagen in December and fell into the Baltic Sea, drunk. Got a great photo though with the Little Mermaid. I do enjoy life! Sorry I degraded Denmark's statue. I suppose it is the same as our Statue of Liberty here in the USA and what I did back then I would never consider today.