Swimwear for Spa Days: How to Choose the Suit for Hot Saunas
A spa is not the beach or the lap pool, where you drift between warm water, bubbling hot tubs, steam rooms and lounge areas, often around other guests, and the heat and sanitisers involved are far harder on fabric than a dip in the sea.
Choosing the right swimwear for a spa means balancing fit, fabric, heat-safety and a little etiquette all at once.
This guide covers exactly what to look for (and what to leave at home), the most flattering and comfortable styles to relax in, how spa heat and chlorine actually affect different fabrics, and how to care for your suit so it stays beautiful season after season.
What makes a swimsuit for spa?
"Spa swimwear" covers a wide range of moments. On a single spa day you might use a heated pool, a hot tub or Jacuzzi, a sauna, a steam room and a relaxation lounge — moving in and out of the water repeatedly rather than swimming laps. At home, a hot tub or swim spa means shorter, more frequent soaks in chemically treated water.
Both call for the same core qualities: a snug, secure fit that stays put when you sit and rise, a quick-drying fabric that doesn't cling or sag, comfort against warm skin, and — importantly — nothing that overheats, traps water or risks a burn. Get those right and everything else is personal style.
Suitable fabrics for spa swimwear
The most comfortable spa suits are made from lightweight, four-way-stretch synthetics that dry fast and hold their shape: nylon (polyamide) blended with elastane, or polyester-based blends. These fibres are quick-drying, stretchy and supportive — the opposite of anything that soaks up water and turns heavy.
Where it gets technical is chlorine and heat. Most spa pools and home hot tubs are sanitised with chlorine or bromine, and not all fabrics cope equally:
| Fabric blend | Feel & stretch | Chlorine & heat resistance | Best suited to |
|---|---|---|---|
| Polyester + PBT | Firm, matte, very shape-retentive | Excellent | Frequent hot-tub and chlorinated-pool use |
| Polyester + elastane | Smooth with good stretch | Very good | Regular spa and pool sessions |
| Nylon / polyamide + elastane | Soft, silky, excellent stretch | Moderate | Spa days, occasional soaks, everyday swim |
| Cotton or cotton blends | Soft but highly absorbent | Avoid | Not recommended for any spa or hot tub |
A useful rule from textile science: polyester is naturally more chlorine-resistant than nylon, because its molecular structure stands up better to the hypochlorous acid in sanitised water, while nylon is more prone to fading and gradual weakening over many exposures.
In every stretch blend, the elastane (spandex) is the most vulnerable component — it's the first fibre chlorine attacks — which is why rinsing and gentle care (more on that below) make such a difference to how long any suit lasts.
The best swimsuit styles for a spa day
Once the fabric box is ticked, choose a silhouette that lets you forget you're wearing it. These styles consistently work well for spa-goers:
One-piece
The most recommended choice for a spa: secure, elegant and stay-put, with smooth coverage that won't budge as you move between pool and lounger. Explore the one-piece swimsuits.
Tankinis
The coverage of a one-piece with the flexibility of two pieces — handy if you like a little extra tummy coverage but want to change quickly. Browse the tankinis.
Wire-free and bralette tops
For pure relaxation, a soft bralette bikini top with no underwire is hard to beat. If you prefer structure and lift, choose a supportive underwire top instead — comfort is personal, so go with what feels effortless to you.
Full-coverage and tummy-control designs
If feeling secure helps you switch off, a tummy-control swimsuit or full-coverage bottoms give gentle support without squeezing.
Inclusive sizing
A great spa suit should fit, full stop. The plus-size swimwear range is designed with the same supportive, quick-dry fabrics.
One styling note worth borrowing: a spa is a rare chance to wear something a little more expressive, because there are no tan lines to plan around. Save the bolder cut-outs and statement straps for poolside and the relaxation areas, and keep things simple and metal-free if you'll be heading into the sauna.
Not sure which level of coverage suits the occasion? The BERLOOK coverage guide makes it easy to compare.
Spa-day Tip:
Check the dress code before buying. Most spas in the UK, US and Australia ask for swimwear in shared, co-ed wet areas. Some facilities have gender-segregated or "clothing-optional" zones, and sauna culture varies widely around the world.
When in doubt, ask the spa — policies differ from venue to venue.
What to avoid in a spa/hot tub
A few materials and details that are fine at the beach become uncomfortable — or unsafe — in a hot, chemically treated, shared environment:
- Cotton and absorbent fabrics. They soak up water, turn heavy, stay cold and clammy, and offer no UV protection outdoors.
- Metal hardware and heavy embellishments. Rings, clasps, buckles and studs can heat up fast in a sauna or steam room and burn the skin; sequins, beads and stiff trims can also dig in or irritate when you sit. Keep jewellery off entirely in the heat.
- Loose string ties and very skimpy cuts. String bikinis tend to shift, ride up or come undone when you climb in and out, so you spend the day adjusting instead of relaxing.
- Sheer or see-through fabric. It offers no coverage in a public setting and provides no sun protection on an outdoor terrace.
- PVC or heavily coated "fashion" swimwear. Vinyl-style finishes can soften or even melt in extreme sauna heat — best avoided around high temperatures altogether.
- Shorts, leggings or layered clothing in a hot tub. Bulky garments trap heat against the body and can leave you uncomfortably warm; a snug swimsuit lets your body regulate temperature properly.
How to care for your swimwear after spa
Heat and sanitisers together are the main reasons swimsuits wear out — but a simple routine dramatically extends a suit's life and keeps colours vivid:
- Rinse in cool fresh water after every single use. This is the most important step. Rinsing straight after your soak washes out the chlorine, bromine and minerals before they can sit in the fibres and break them down.
- Hand-wash gently in cool water. Skip regular detergent, chlorine bleach and fabric softener — they strip protective finishes, can fade colour and add contaminants you don't want near spa water. A little mild swimwear wash is plenty.
- Dry flat in the shade. Never wring or twist your suit, and keep it out of the tumble dryer and direct sun. High heat and UV are hard on elastane and accelerate fading; reshaping and drying flat preserves both stretch and colour.
- Rotate your suits and avoid rough surfaces. Letting a suit fully dry between wears helps the elastane recover, and sitting on smooth surfaces rather than rough concrete prevents snags and pilling on chlorine-softened fibres.
Spa swimwear care, at a glance
- Do: rinse in cool water immediately · hand-wash gently · dry flat in the shade · rotate between suits
- Don't: use bleach, detergent or fabric softener · wring or twist · tumble-dry · leave it bunched up and wet
Frequently Asked Questions
Can you wear a bikini in a hot tub?
Yes — a bikini is perfectly fine in a hot tub as long as it fits snugly and is made from a quick-dry synthetic like nylon-elastane or a polyester blend. Avoid loose string ties that can shift or come undone, and skip metal hardware if you'll also be using a sauna.
Is it chic to wear a swimsuit in a sauna?
For sure yes. In most gyms, hotels and co-ed spas, a lightweight swimsuit is the standard choice for a sauna.
Does a hot tub ruin swimsuits — and how can I protect mine?
The heat and sanitisers in a hot tub can wear fabric down over time, especially the elastane. You can dramatically slow this by rinsing your suit in cool fresh water immediately after every soak, hand-washing gently without detergent or bleach, and drying it flat in the shade rather than in a hot dryer or direct sun.
