After diving, particularly if you’ve been in cold, deep water, the thought of relaxing in the Jacuzzi or taking a super-hot shower might sound appealing. And, since water in the hot tub isn’t terribly deep, you might think that warming yourself in a bubbling whirlpool would have no effect on the gases that have accumulated in your blood while diving. The same goes for a hot shower – after all, you’re not even immersing your body in water while showering, so what harm could you be doing? Here, we’ll take a look at why it might be a good idea to think twice before heading straight for a hot shower or a hot tub right after a dive.
Decompression Stress
As you ascend from depth, your body is under stress, even if you can’t really feel it. The stress on the body’s tissues doesn’t stop once you reach the surface. Instead, it continues until all accumulated gases have had the chance to exit the body. Changing the body’s condition rapidly by adding heat can cause decompression stress to increase – and it can lead to DCS symptoms if you’re not careful. Although many people head straight for the shower or Jacuzzi after diving with zero consequences, it’s better to be safe than sorry. Getting into hot water right after diving alters decompression stress, and depending on the inert gas load in your body, that could be a problem.
Inert Gas Elimination
Hot water warms the extremities and helps to enhance peripheral circulation, which in turn can facilitate inert gas elimination. This isn’t normally a problem if tissues are not carrying a large gas load, but if you do have a large peripheral inert gas load, then warming the body too quickly can cause bubbles to form, leading to DCS.
This is because the solubility of gases is inversely related to temperature – and the warmer tissues are, the less capable they are of containing gases. The tissues release gas faster than blood can carry it away, and when inert gases wash out too quickly, decompression stress increases.
There is no formula available to determine whether your peripheral inert gas load is minor, moderate, or major. Conditions such as thermal protection, dive profiles, and your own level of physical fitness and physical activity come together to create this load, and it’s different for everyone.
It’s a good idea to stack as many factors as possible in your favor whenever the potential for decompression sickness threatens, and there are a few different things you can do to prevent the pain and damage bubbles resulting from exposure to hot water can inflict on the body. First, if you know you’re going to head straight for the shower or the hot tub after diving, try to stick to a conservative profile. Second, lower the temperature in the shower or the hot tub. If you’re very cold, it is best to allow your body to warm slowly. Third, give yourself fifteen minutes to half an hour before jumping into that hot water. Delaying gratification for a short time can make a huge difference and keep you from experiencing the discomfort of DCS.