Now ya did it.. got my curiosity up...

> It's relative to the DIFFERENCE in the temperature of the water and
> how hot the shower is.  That was the subject of controversy between
> the Aggressor Fleet (no hot tub) and the PhD Fleet (hot tub).  A bunch
> of Docs for Dan concluded for WARM water diving (as in the dive
> locations served by those fleets, the effect is probably negligible.
> BUt even so, they conservatively recommended to wait 30 minutes before
> jumping into the hot tub or hot shower of temperature difference of
> 15 or more degrees F.

This seems logical to me.  My theory would have to do with the constriction
and expansion of the blood vessels that occurs while maintaining the body's
temperature.  When the variation between the water temperatures (dive vs.
shower etc) is lower, there would likely be less change in the blood flow as
a result of temperature regulation.

> >...hmmm, I just did a search on Scubadoc and turned up with this URL
> >http://www.gulftel.com/~scubadoc/prvndcs.htm  with this quote:
>
> >"There is no evidence that shows that a hot shower after diving
> >increases the rate of decompression sickness. "

Got to agree with Da Feeesh on this one.. based on very limited research
there is no evidence that shows that a hot shower after diving DOESN'T
increase the rate of decompression sickness either.

Amusingly there is even a contradictory (IMHO) comment further down...

> There are other factors that are thought to increase the chances
> of getting DCS but have little data in support; some of these are:

<snip>

> Injury to muscle, bone or joint (due to increased blood flow to inflamed
area)

hmmmm.... seems contradictory to me.  They are concerned about increased
blood flow.  Similarly, if the body increases blood flow to the periphery as
a cooling measure, doesn't it follow that a hot shower causes increased
blood flow, the extent controlled by the temperature differential, possibly
increasing the risk?

Granted the website indicates that there is little data to support the
injury/blood flow hypothesis... but consider exercise before and after
diving.  If I'm not mistaken, there is data that supports this as increasing
the risk.  What is the mechanism that makes this increase the risk? Is it
the increased blood flow that results?.. hmmmmm... I don't know but in light
of this I'm sure tempted to be careful about rapid changes to my body
temperature after diving.

Steve