Float Boston · Somerville, MA
Contrast therapy.
Heat. Cold. Reset.
A private suite with an infrared sauna reaching 200°F — with red light therapy built in — and a cold plunge held at 44°F. One of the most powerful recovery tools available — now in Somerville.
Buy a founder's package, membership or session and you'll get VIP pre-launch access!
What is it
Hot and cold.
The oldest recovery tool there is.
Contrast therapy alternates between heat and cold to trigger your body's natural healing response. The concept is ancient — Finnish sauna culture, Nordic plunges, Roman baths — but the science behind it is modern and well-documented. When you heat the body, blood vessels dilate and circulation surges. When you plunge into cold, they constrict sharply. Alternate that cycle and you create a powerful pumping effect through your entire vascular system, flushing metabolic waste, reducing inflammation, and delivering fresh oxygen to muscles and tissues.
At Float Boston, we've built this around two things that make the experience meaningfully different from anything else in the area: an infrared sauna that reaches 200°F with built-in red light therapy, and a cold plunge held at 44°F. The infrared heat penetrates up to two inches into your tissue — not just warming the air around you, but heating your body from the inside out. That deeper internal heat creates a more pronounced thermal contrast, which amplifies every benefit when you hit the cold plunge.
Timers are built into the room to guide your rotations. You don't have to think about it — just follow the rhythm, stay hydrated, and let your body do the rest. Finish with the vitamin C filtered shower and you leave feeling like a different person.
Infrared sauna
Infrared light penetrates up to two inches into tissue, warming you from the inside out rather than heating the air around you. At 200°F, you'll experience deep muscle relaxation, increased circulation, and a detox sweat that primes your body for everything that follows. The red light layer adds cellular repair and collagen stimulation — benefits that continue working after you leave.
Cold plunge
At 44°F, our cold plunge is among the coldest available — well below the 50–60°F range many facilities maintain. The cold triggers sharp vasoconstriction, a flood of norepinephrine and dopamine, and a powerful inflammatory reset. Most people start with 30–60 seconds and build from there. The first few seconds are the hardest. What follows is something most people don't have a word for yet.
Post-session shower
Every session includes time in our vitamin C filtered shower — the same upgrade used by leading contrast therapy studios. Vitamin C neutralizes chlorine, supports skin elasticity, and gives hair and skin a noticeably softer finish. It's a small detail that makes a real difference, especially after your body has been through the heat-cold cycle.
Why do it
What contrast therapy actually does
The evidence is strong. Here's what consistent contrast therapy practice is associated with.
Muscle recovery
Research shows cold water immersion can reduce post-exercise muscle soreness by 20–60% compared to passive rest. The alternating vascular cycle flushes metabolic waste and delivers fresh oxygen to damaged tissue faster than rest alone.
Circulation boost
The heat-to-cold alternation creates a pumping effect through your blood vessels — expanding and contracting them in repeated cycles. Over time, this improves vascular flexibility and cardiovascular efficiency. Studies show heat exposure alone can increase blood flow by up to 30%.
Inflammation reduction
Cold immersion reduces systemic inflammation by constricting blood vessels and slowing the cascade of inflammatory signals. For people managing chronic pain, joint issues, or post-training soreness, this is often the most immediately noticeable effect.
Mood and mental clarity
A cold plunge can raise dopamine levels by up to 250% — a finding from research published in Neuroscience Letters. Paired with the endorphin release from heat, the contrast session produces a mental clarity and mood lift most people describe as unlike anything else. No caffeine required.
Stress and cortisol
Regular heat therapy has been shown to reduce cortisol levels by more than 25%. The sauna environment forces stillness — no screens, no noise, nowhere to be. Combined with the cold plunge's nervous system reset, contrast therapy is one of the most effective stress management tools available.
Sleep improvement
The drop in core body temperature that follows a cold plunge closely mimics the physiological process that triggers sleep onset. Evening contrast sessions — ending at least two hours before bed — are associated with faster sleep onset and improved sleep quality.
Built into the sauna
Red light therapy.
The third layer.
Most contrast therapy studios offer heat and cold. Our sauna adds a third dimension: red light therapy operating at the 660nm wavelength, clinically studied for its effects on cellular repair and recovery. While the infrared heat works on your muscles and circulation, the red light is simultaneously working at the cellular level — stimulating mitochondria to produce more ATP, accelerating tissue repair, and reducing inflammation from the inside out.
You don't have to do anything differently. It works passively while you're in the sauna — no additional time, no extra steps. It's just part of the session.
Cellular repair
Red light at 660nm penetrates skin and tissue to stimulate mitochondria — the energy centers of your cells. More ATP production means faster cellular repair and regeneration, compounding the recovery benefits of the heat and cold cycle.
Collagen & skin
Red light is clinically associated with increased collagen production, improved skin tone and texture, and reduced fine lines and inflammation. Every sauna session doubles as a skin health treatment.
Inflammation relief
Red light reduces inflammatory markers at the cellular level — working alongside the cold plunge's vascular response for a two-pronged attack on soreness, joint pain, and chronic inflammation.
Mood & brain health
Red light has neuroprotective effects — enhancing cognitive function and mood regulation by improving mitochondrial function and circadian rhythm regulation. Stack this with the dopamine hit from the cold plunge and the effect is pronounced.
Most standalone red light therapy studios charge $25–$50 per session. At Float Boston it's included in every contrast session at no extra charge — built into the sauna, every time.
Why Float Boston
Private. Powerful.
Built differently.
Most contrast therapy studios charge per person, run shared spaces, and cap you at 60 minutes. We do none of that. When you book contrast therapy at Float Boston, the entire suite is yours.
The ultimate reset
Float before or after.
Feel the difference.
Contrast therapy and float therapy are powerful on their own. Together they cover everything — physical recovery, nervous system reset, inflammation, sleep, mood, and mental clarity — in a single visit.
Both services run on the same schedule, so pairing them is seamless. We book them back to back with a natural transition window between.
Contrast before float: The infrared sauna opens up your muscles, vasodilates your vascular system, and the red light layer begins working on cellular repair while you sweat. The cold plunge then settles your nervous system sharply. By the time you enter the float tank, your body drops into deep relaxation faster — most people describe this as the deepest float they've ever had.
Float before contrast: The float disconnects you completely — zero input, zero gravity, total stillness. Moving directly to the contrast suite while that calm is still in your system extends the nervous system reset and adds the physical recovery layer. Your body is primed to absorb the benefits of both.
Combined benefits: Full-body inflammation reduction, peak dopamine and endorphin release, deep muscle recovery, extended nervous system downregulation, improved sleep, and mental clarity that lasts through the day.
Book both
Float + Contrast.
Same visit.
Book a float and a contrast session back to back. They run on the same schedule, so the transition is seamless — just let us know when you book that you'd like both.
See founder's pricing →Questions? Call or text us at 617-875-0725
Pre-launch pricing
Founding rates.
Limited availability.
These prices are available for a limited time only. All offers end Memorial Day. Once they're gone, regular pricing applies. Founding members keep their rate as long as membership stays active.
Drop-in sessions
Monthly memberships — founding rates
All memberships include: priority booking, discounted additional sessions, and your rate is locked in as long as membership stays active.
FAQ
What to expect
Contrast therapy alternates between heat and cold exposure to trigger your body's natural healing and recovery responses. Heat causes blood vessels to dilate, increasing circulation and relaxing muscles. Cold causes them to constrict sharply, reducing inflammation and triggering a release of dopamine and norepinephrine. Cycling between the two creates a powerful vascular pumping effect that accelerates recovery, reduces soreness, and resets your nervous system. At Float Boston, that means moving between our infrared sauna at 200°F and cold plunge at 44°F — with timers in the room to guide your rotations.
The most well-documented benefits include reduced muscle soreness and inflammation, improved circulation, a significant boost in dopamine and mood (cold plunges can raise dopamine levels up to 250%), lower cortisol and stress hormones, improved sleep quality, and stronger immune function. Red light therapy — built into our sauna — adds cellular repair, collagen stimulation, and anti-inflammatory benefits at the tissue level.
For beginners, start with 30–60 seconds and build from there. Most regular users work up to 2–3 minutes per plunge. At 44°F, our plunge is colder than most facilities — which means the physiological benefits kick in faster. The timers in the room are calibrated to guide you through a balanced session, so you don't need to figure out the timing yourself.
Each session is 60 minutes in the suite, followed by time in the vitamin C filtered shower. The suite is private and booked exclusively for you, so there's no rushing or waiting for equipment.
Yes — and at no extra charge. The suite accommodates up to 2 people at the same price. Most competitors charge per person, which means a couple visiting SWTHZ pays $140–160 for a single session. At Float Boston, two people pay the same rate as one. Great for couples, training partners, or friends.
Wear a swimsuit or athletic shorts you're comfortable getting wet. We provide towels. Bring a water bottle — staying hydrated is important during contrast therapy. Shower products are available in the suite. You don't need to bring much — we take care of the rest.
Research supports 2–4 sessions per week for most people. Once a week is enough to feel consistent benefits. Four times a week is where the cardiovascular and long-term recovery effects really compound. Like most wellness practices, the results build with consistency — one session is great, a regular routine is transformative.
Contrast therapy is safe for most healthy adults. We recommend consulting your doctor first if you have heart conditions, are pregnant, have blood pressure concerns, or are taking medications that affect circulation. During your session, listen to your body — if you feel dizzy or unwell, exit immediately. Our staff is nearby and happy to answer questions before you start.
Red light therapy uses specific wavelengths of light — primarily 660nm — to penetrate skin and tissue and stimulate cellular energy production. At the cellular level it activates mitochondria to produce more ATP, which accelerates tissue repair, reduces inflammation, supports collagen production, and improves circulation. At Float Boston, red light therapy is built directly into the infrared sauna, so it works passively throughout your session — no additional time required, no extra setup. Benefits include faster muscle recovery, improved skin tone, reduced joint pain and inflammation, and better mood. Most standalone red light studios charge $25–$50 per session; here it's included in every contrast therapy booking.
The plunge is fully drained, cleaned, and refilled between sessions. We use advanced filtration and ozone sanitation to maintain water quality, and water chemistry is tested daily. The same rigor we apply to our float tanks — which are among the strictest sanitation environments in wellness — is applied here.
Absolutely — and we think it's one of the best things you can do for yourself. Both services run on the same schedule, so they pair seamlessly with a natural transition between them. Contrast before float primes your body for deeper relaxation in the tank. Float before contrast extends the nervous system reset and adds full physical recovery on top. Book both and let us know at booking — we'll schedule them back to back.
Yes — the contrast suite is a single private room, so availability is limited. We recommend booking in advance to guarantee your slot, especially on weekends. Same-day bookings may be available depending on the schedule. You can book online anytime at floatboston.floathelm.com.
Ready to try it
Your first session.
$40.
Private suite. Up to 2 people. 60 minutes of infrared sauna, red light, and cold plunge. Founder's pricing ends Memorial Day.
Questions? Call or text 617-875-0725 · 515 Medford Street, Somerville MA