Posted by Eric Frasco on June 15, 2001 at 12:54:39:
In Reply to: If we scare people away from the hot tub -- more room for me! posted by Wayne on June 15, 2001 at 10:53:42:
Folks:
Soda contains dissolved gasses in what is called a "super-saturated" condition. These gasses are perfectly happy in solution until something happens to the liquid (like releasing the pressure by opening the bottle). At that point the gasses come out of the liquid in the form of bubbles.
For example, I am sure all of you know what happens when a soda (not shaken) at room temperature is poured over ice - it foams up! Gas comes out at a much faster rate when the liquid is abruptly cooled.
The reason the soda foams up is due to the fact that super-saturation is temperature dependent. The higher the temperature of the liquid, the more gas it can hold. The lower the temperature, the less gas it can hold.
So warming your core body temperature back up to normal should -theoretically- reduce the likelyhood that bubbles will form.
Now, about bubbles expanding with an increase in temperature. This implies that bubbles have already formed. If you have large free moving bubbles in your blood stream, then you are probably already bent. As far as a change in size of such bubbles, for bubble to expand significantly you have to have a significant change in temperature (I'll spare you the boring details, but to double the volume - not diameter- of a bubble essentially requires nearly a 300 deg. C temperature change). The bottom line is you would cook before the bubble reaches twice its orginal volume. Pressure changes are a much more significant factor is determining bubble size.
Of course, what happens in physics is not necessarily what happens in physiology, and there are many other factors in volved in bubble formation in the blood stream and tissues.
Many years ago, it was common practice to place divers with DCS in a bed of ice while transporting them to a medical facility (think back to the warm soda on ice example above). In fact, it was used when divers working on the filming of Kevin Costner's Waterworld movie got bent. It just goes to show how little is really known about how to properly treat DCS.
All the more reason to get to a proper recompression facility the moment you decide (or think) you are bent.
-Eric-