Nothing like a nice soak in a hot tub after a long, hard workout or a swim in a cold pool, is there? Before you indulge, consider this: Chlorine and other disinfectants used to kill germs break down faster in the warm water of a hot tub than they do in a swimming pool.

That raises the risk of infections, such as those triggered by the bacterium Pseudomonas aeruginosa. Here's what you need to know to avoid hot tub health problems.

Watch Out for These Hot Tub Infections

Hot tub rash, a bacterial infection that you can pick up in a hot tub, causes bumpy, red itchy spots and pus-filled blisters, especially on skin that's covered up by a bathing suit. The rash normally clears up on its own in a few days, but can require medical attention if it persists longer than that.

In addition, the steam and bubbles wafting from the surface of a hot tub can launch bacteria into the air, potentially causing respiratory infections that doctors have dubbed hot tub lung. These include Legionella, which causes Legionnaires’—a form of pneumonia. This may be more likely at indoor tubs, where air circulation is limited.

Protect Yourself in Hot Tubs

It’s worth asking your health club operator about tub maintenance before you soak. When tub operators keep the water’s pH (the alkaline/acid balance) at proper levels and disinfect as recommended, infection risk is low, according to the Centers for Disease Control and Prevention.

So, ask if both are checked at least twice a day, and more often when many people are using the hot tub. In addition, ask whether the water and water filter are replaced regularly and how often the tub is cleaned and scrubbed, too.

It’s smart to change out of your bathing suit and shower as soon as you exit the tub; be sure to wash your suit as well. And remove your contact lenses. Hot tubs can expose lens wearers to the organism that causes Acanthamoeba keratitis, a rare eye infection that can damage vision or even cause blindness. These critters are resistant to chlorine at the levels found in hot tubs.

When to Skip the Hot Tub

If you have high blood pressure and your doctor has recommended that you avoid moderate exercise, it may be wise to avoid hot tubs as well. Your blood pressure could drop sharply as the hot water opens blood vessels close to the surface of your skin. Skip the soak if you have broken skin or low immunity, too.

Otherwise, unless your doctor has advised against it, whether or not to soak in a hot tub is up to you. But be aware of this sobering piece of information: Researchers note that the complex plumbing of a hot tub may be difficult to clean thoroughly enough to remove sticky colonies of bacteria.