Algorithms & Tempertaure

[wibble32]

Does Nitrogen take up in tissues get affected by body temperature?

If yes where in C water temperature does this start to matter and do the standard near Buhlmann algorithms used in popular DC's take this into account?

Any info or references welcomed. I could not find anything in Deco for Divers.

Rgds

[Paulo]

Yes, being warmer allows quicker on and off gassing. This is why in theory, being cooler on the bottom and warmer in the shallows is good and is much better than being hot at depth and very cold in the shallows (eg heated vest turned on on the bottom and suit flood on deco).

That being said, I do not think there is a magic "add 5mins to your stops here at X⁰C" formula out there.

[wibble32]

Yes, being warmer allows quicker on and off gassing. This is why in theory, being cooler on the bottom and warmer in the shallows is good and is much better than being hot at depth and very cold in the shallows (eg heated vest turned on on the bottom and suit flood on deco).

That being said, I do not think there is a magic "add 5mins to your stops here at X⁰C" formula out there.

Thanks.

That was my thinking but wondered if the science and numbers had caught up. North Sea diving V Red Sea diving etc.

[Neilwood]

AFAIK none of the popular algorithms take account of temperature.

What the research (from what I remember from a number of videos of lectures from a number of experts in the field
- Neil Pollock )

seems to show though is that cold=slow ongassing and offgassing and warm=quicker ongassing and offgassing. If the diver's temperatures are fairly similar during both phases or the diver is cold on entry (slow ongassing)/warm on exit (faster offgassing), the risk from temperature is fairly low. The worst risk therefore is where a diver starts warm (higher ongasing) and ends cold (slower offgassing).

The exact extents of these effects are AFAIK very hard to model because of a relatively small sample size (on the temperature issues) and the huge differences in physiology between divers.

[nigel hewitt]

The classic skin bend is diving nice and warm so you skin on gasses but then your skin gets cold and the blood vessels contract to reduce heat loss so you off gas much slower.

To actually get a temperature swing enough to mess with the physics of gasses entering and leaving solution in your lungs you would be dead already.

[Tim Digger]

It's not really the temperature changes of core temperature is diffusion changes but the vasoconstriction a normal response to even 2or 3 degree drop in core temperature is perfusion changes. Since degree of vasoconstriction is very variable for a given call in core temp the whole thing is impossible to model so any sort of alterations to tables or computers is finger in the air stuff to measure wind speed.

[N Bailey]

The UWATEC range took temperature into account in the algorithm