Health Expert Warns “You Should Never Get In a Hot Tub Again”

Hot tubs look like luxury. To Thomas Seager, PhD, they look like a petri dish with mood lighting.

On Danny Jones’ podcast, Seager lays out a blunt case: most hot tubs are chemically imbalanced, biologically risky, and engineered in ways that fight – rather than support – human health. 

Jones pushes, prods, and asks the obvious questions. Seager answers with chemistry, physiology, and a radically different blueprint for “safe soaking.”

The Nice-Feeling Bath With a Dirty Secret

Seager opens with a gut punch. “There are hot tubs all over this country and they feel great, but they make you sick.” He isn’t being coy. 

He lists the “three things wrong” with conventional tubs: missing minerals, the wrong redox (oxidation-reduction) environment, and no grounding to the earth.

That first point is deceptively simple. Natural hot springs come loaded with dissolved minerals, especially sulfate salts, that change the water’s feel and chemistry. Your standard backyard or hotel spa? “Chlorinated, fluorinated tap water,” Seager says. It’s sterile-looking, not spring-like.

Jones steps in as the everyman. Hot tubs relax tight backs. They’re social. They’re everywhere. So what’s the harm?

Seager’s answer isn’t fearmongering. It’s mechanics. Warm water strips your skin’s oils. Body lotions, sweat, cosmetics, and shed skin cells turn into a buffet for bacteria. Add high bather loads, inconsistent sanitizer levels, and you’ve created paradise for Pseudomonas (hot-tub rash), eye/ear irritants, and – in worst cases – Legionella. 

Even vigilant owners struggle once biofilms take hold, because those slimy microbial fortresses shield bacteria from chlorine.

My take is that this isn’t alarmist. Public health departments publish similar cautions every year. The difference here is Seager’s insistence that design – not just diligence – sets the stage.

Chlorine Isn’t the Hero You Think It Is

Seager’s second critique is nerdy but important: the oxidation-reduction potential (ORP) of the water. Chlorine raises ORP, creating an oxidative environment that kills microbes. Natural springs, by contrast, often skew reductive, thanks to sulfur and sulfate chemistry. In Seager’s telling, your body likes that reductive, electron-donating bath far more than a highly oxidative soak.

He’s not saying “never sanitize.” He’s saying we’ve mistaken “maximum oxidant” for “optimal health.” And we double down at hot-tub temperatures, where chlorine degrades faster and needs more frequent dosing to keep up.

Jones plays the foil again: if you lower the oxidants, don’t you just invite more germs?

Seager proposes a different architecture: sanitize with ozone when you need disinfection, then switch the system to infuse dissolved hydrogen and add sulfate minerals (think Epsom salt) for soaking. 

Ozone off, hydrogen on. The water’s ORP flips reductive. In his view, you get clean water plus a redox environment closer to a hot spring.

I’m sympathetic to the spirit – design around health, not just convenience. But it’s fair to say hydrogen bathing and “therapeutic redox” are still contested topics in mainstream medicine. 

If you’re going this route, do it eyes-open and keep a test kit handy. Clean water comes first.

What Your Skin and Blood Vessels Do Underwater

Seager’s third critique is the most surprising: physiology in a hot tub is not sauna physiology. In a sauna, you cool by sweating and get vasodilation – blood vessels widen to dump heat. In a hot tub, you can’t evaporate sweat underwater. 

“Everything saturated with water cannot sweat,” Seager says. So the body defends by vasoconstriction – tightening blood vessels – even though you feel warm.

Translation: your cardiovascular system experiences a different stimulus than you probably think. If you want maximum “vascular workout,” Seager argues, go contrast: dry heat (sauna) followed by cold (ice bath). 

He calls it a smooth muscle workout for your blood vessels.

Jones admits he kind of wants a hot tub anyway. Seager doesn’t entirely object. Hydrotherapy has a real history. 

He tells the Jacuzzi origin story – an immigrant father engineering whirlpool jets at home to relieve his young son’s rheumatoid arthritis pain. It’s a lovely snapshot of practical ingenuity.

But Seager insists today’s health landscape is different: more chronic oxidative stress, more seed oils, more modern inflammatory load. In his framework, ice baths—by ramping metabolism and lowering oxidative stress—map better to modern needs than an hours-long chlorinated soak.

I appreciate his clarity: hot tubs can feel great and help sore muscles, but they’re not a panacea. Use the right tool for the job.

The Case Against Hotel and Gym Spas

Here’s where the warning label belongs. Seager calls out public and high-traffic tubs – hotels, gyms, vacation rentals – as special risks. 

Why? Crowds accelerate the biofilm problem, sanitizer demand spikes, and “the strong chlorine smell” people associate with cleanliness often signals the opposite: chloramines and combined disinfectants that irritate eyes and lungs.

Jones asks the practical question every traveler has: how do you know when to skip it?

Seager’s quick checklist is refreshingly actionable:

• Cloudy or foamy water? Skip.
• Crowded tub? Skip.
• Strong chemical odor? Probably chloramines. Skip.
• No posted readings for sanitizer and pH? Skip.
• Visible slime around jets or tile lines? Hard skip.

He goes further for home owners: test sanitizer and pH before you soak, not after; bromine holds up better than chlorine at higher temps; mechanically disrupt biofilms (think filter changes, line flushes); and treat “crystal clear” as a starting point, not proof of safety.

My view: this is the best part of the conversation. No product pitch. Just habits that reduce your risk immediately.

From “Never Soak Again” to “Soak Smarter”

The title of the episode promises absolutism – “never get in a hot tub again” – but Seager’s actual position lands more nuanced. 

He wants to replace chlorine-heavy, ungrounded acrylic boxes with what he calls a “hydrogen mineral bath”: warm, mineralized, reductive, and electrically grounded to the earth. He says his company’s model checks those boxes, though he also admits it’s “incredibly expensive” and currently priced for athletes and early adopters.

Jones keeps the conversation honest by pointing out the price tag and asking whether a sauna would be a better buy for most people. Seager, to his credit, doesn’t dodge. 

For thermal contrast and cardiovascular benefits, he recommends sauna plus cold. For people who will never get in an ice bath – he jokes about convincing spouses – the hydrogen mineral bath aims to deliver some of the same oxidative stress relief in a friendlier package.

There’s also a subtle point worth underlining: grounding. Conventional acrylic or fiberglass tubs isolate you electrically from the earth. Seager argues that a grounded vessel restores that electron flow. 

This idea is popular in wellness circles and debated in mainstream circles. If you’re intrigued, treat it as a “maybe useful” rather than settled science – and never compromise on electrical safety in wet environments.

My Bottom Line: Treat Hot Tubs Like Sushi

That sounds flippant, but it’s the best framing I’ve found after hearing Seager out. Hot tubs can be delightful. They can also make you sick if the operator cuts corners. So apply sushi rules:

• Know your source. A well-maintained private tub with posted logs and fresh filters beats a mystery hotel bath.
• Smell and look. If it stinks or looks off, walk away.
• Temperature matters. Higher temp = faster sanitizer burnoff = more diligence required.
• Timing matters. Avoid peak crowds. Freshly balanced water is safer than end-of-day stew.
• Ask questions. A good spa manager will show you the sanitizer and pH readings without blinking.

Where Seager is most convincing is the design critique. We built tubs for convenience, not health. If you own one, you can nudge it in a better direction today – better testing, bromine in high-temp setups, periodic line cleaning, and mineral supplementation where appropriate. 

If you’re shopping, don’t be dazzled by LEDs and waterfalls. Ask about filtration, biofilm control, sanitizer strategy, and maintenance access.

And if you’re chasing whole-body benefits, Jones helps tee up the honest tradeoff. For cardiovascular training and metabolic effects, sauna + cold is still the heavyweight. 

For muscle comfort and relaxation, a clean, well-run tub is a worthy tool. Just don’t confuse “bubbles feel nice” with “this must be good for me.”

Seager’s strongest message isn’t “never soak.” It’s “stop pretending the chlorine smell is cleanliness,” respect the microbiology, and design for human physiology, not Instagram aesthetics. On that, I’m fully with him.