In-suite cold immersion for hotels and spas

Cold immersion, in the tubs you already have.

HotelPlunge turns a guest suite's bathtub or a spa tub into a precise cold plunge, down to 34°F. No renovation. No plumbing. No room out of service.

Book a 15-minute call Request a Carillon walkthrough
The HomePlunge chiller at a freestanding tub
In residence at Carillon Miami Wellness Resort The Santaluz Club JW Marriott Desert Springs
For general managers and owners

The amenity your comp set can't copy without a construction permit.

Cold plunge has moved from niche recovery to a searched-for amenity. Most properties don't offer it because a plunge facility means capex, permits, engineering and revenue rooms offline. This is the version without any of that.

i.

What it does for the property

A distinctive in-suite amenity to name in OTA listings, on your site and at the front desk. Wellness-minded guests choose properties that program recovery, and very few in any market can offer it in the room.

ii.

What it costs to try

One unit, one suite. It rolls in on wheels, connects to the existing tub with two insulated hoses and plugs into a standard outlet. If the pilot doesn't earn its keep, it rolls back out. Nothing to un-build.

iii.

What it asks of housekeeping

Drain the tub after each guest, exactly as the team already treats a bathtub. Fresh water for every guest, so there is no shared-water question at the front desk. The filter is reusable and rinses every 4 to 6 weeks: nothing to stock.

iv.

What it risks

No plumbing modification, no permits, no structural change. Guests use a bathtub the way they already do, only colder, with the first cold plunge to win a CES Innovation Award.

34°FPrecise temperature
5 minSetup, no contractor
2 × 2 ftBeside the tub
30 minTap water to 50°F
ZeroRooms out of service
The return

Your rooms already have the tub. Price the plunge by the night.

Enter the rooms at your property that have a bathtub. The calculator starts from an average night, with 2 percent of guests in those rooms booking a plunge at the average US hotel occupancy. Then it sizes the fleet for your busiest nights: peak season, event weekends and team stays.

Suites and rooms where the tub is separate from the shower work best, so the shower stays free.
%
62.3% is the US hotel average for 2025 (CoStar). Use your own figure if you know it.
The share of occupied tub rooms that order it from the card on the nightstand. 2% is our planning case.
$
Set by the property and billed to the folio.
A visiting team or group that stays together. Athletes book recovery far more often than other guests.
Guest revenue, year one
$0
0Tub rooms occupied a night
0Plunges booked a night
0Units for an average night
Guest revenue, year one$0
HomePlunge units, bought once$0

Talk through these numbers Email me this estimate

Plan the fleet for your busiest nights.

The average night is the starting point. Choose the night you want to be ready for; the cost and payback above follow your choice.

Illustrative, not a forecast. Guest revenue is bookings a night times the guest price, 365 nights a year, before the property's own costs such as delivery labor, water and power. Revenue counts average nights only, so plunges sold on busier nights by a larger fleet are upside on top. Busier-night assumptions: peak season at 95 percent occupancy with 1.5 times the bookings; an event weekend (a race, a tournament, a conference) sold out with twice the bookings; a team or group stay where 8 in 10 rooms in the block book, on top of a normal night for everyone else. Units are rounded up. Unit cost uses the HomePlunge H3 list price of $2,999; commercial pricing, warranty for revenue-generating use and support terms are agreed in writing before any unit enters a room. Occupancy default: US hotel occupancy for 2025, 62.3 percent, CoStar, January 2026.

One night, in the room

The guest books it from the nightstand. Housekeeping does the rest.

A card by the bed with a QR code. The guest picks a temperature and a time, then goes out for the day. Housekeeping rolls the unit in, fills the tub and sets it while the room is empty. Drained and retrieved at checkout.

Storyboard: a guest checks in and reads the in-room cold plunge card on the nightstand

0112:00 PMChecks in and finds the card on the nightstand: a private cold plunge, $199 a night.

Storyboard: the guest scans the card and books a 50°F plunge for 10:30 PM on his phone

0212:05 PMScans it, sets 50°F, ready by 10:30 PM. Then heads out for the day.

Storyboard: the guest playing golf on a desert course

031:00 PMOut for the day. The room is the last thing on his mind.

Storyboard: a housekeeper rolls the HomePlunge unit down the hotel corridor

042:15 PMHousekeeping rolls HomePlunge to his room. No tools, no work order.

Storyboard: the guest applauding at an evening show

068:00 PMDinner and a show. He hasn't thought about the room once.

Storyboard: the housekeeper fills the bathtub and sets the HomePlunge to 50°F

052:30 PMFills his tub and sets 50°F. It chills, then holds all evening.

Storyboard: the guest returns to find the cold plunge ready beside the tub

0710:30 PMBack in the room. His plunge is ready and waiting.

Storyboard: the guest in the cold tub taking a photo

0810:45 PMPosts it and tags the hotel. Checks out with five stars.

Nothing is installed and no room comes out of inventory. If it does not sell, the units roll out and the bathrooms are exactly as they were.

Run your numbers
For spa and wellness directors

The recovery modality your menu is missing.

Cold exposure is the most requested recovery treatment many spa menus still lack. HotelPlunge lets you program it without a build-out.

Complete the contrast circuit

Pair cold immersion with the sauna and steam you already run, in the spa or in the suite.

A recovery suite category

Position one or two suites as recovery suites at a premium rate. Bundle with late checkout for race weekends and team stays.

A modality guests already know

The same equipment professional athletes use through NFLPA and MLBPA partnerships. Being the property that actually has it is the point.

In residence
The HomePlunge chiller beside the stone plunge tub in the spa at Carillon Miami Wellness Resort
The spa at Carillon Miami Wellness Resort
Miami Beach, Florida

Carillon Miami Wellness Resort

South Florida's flagship wellness resort runs HotelPlunge in its spa's contrast circuit, beside the infrared sauna. The chiller connects over the edge of a stone spa tub. No plumbing work was done.

The same unit connects to a guest suite's bathtub at your property. If you operate nearby, don't take our word for it: ask for a walkthrough.

Request a walkthrough
San Diego, California

The Santaluz Club

Running at The Santaluz Club, connected to an existing tub in the same way: two hoses over the rim, a standard outlet, nothing built.

Palm Desert, California

Phase one ordered by JW Marriott Desert Springs Resort & Spa for Spa Desert Springs, so hot and cold run side by side.

The Desert Springs plan
The HomePlunge chiller at a tiled bathtub at The Santaluz Club
The Santaluz Club, San Diego
The equipment

One unit. Every tub your property has.

The HomePlunge H3 connects to an existing tub with two insulated hoses and plugs into a standard outlet. Scheduling and temperature run from an app, so the spa or front desk can prepare a session before the guest arrives. Indoor use, never any winterizing.

HomePlunge H3 chiller beside a freestanding bathtub
For hotels and spas

HomePlunge H3

The unit installed at Carillon Miami
  • Coldest set point 34°F
  • Tap water to 50°F About 30 minutes
  • Tap water to 34°F About 1 hour 20 minutes
  • Size 18.35 × 16.38 × 20.65 in
  • Filter Reusable, no consumables

Built for same-day turns: housekeeping drains after checkout and the room is cold before the next guest arrives.

Power

A standard 110V outlet. The H3 draws 9A. No electrician, no dedicated circuit, no engineering ticket.

Weight

About 112 lb on casters, so one person repositions it.

Sound

65 to 75 dB while actively cooling, about the level of conversation. Schedule it to run before the guest returns.

Recognition and partners

Credentials your guests already recognize.

CES Innovation AwardThe first and only cold plunge to win at CES. 2025 Honoree.
TIME Best InventionsSpecial mention, 2025.
Garage Gym ReviewsNamed Best Indoor Cold Plunge, with the highest score of any plunge on the list.
NFLPA, MLBPA, MLSPAPartnerships with the players' associations of the NFL, MLB and MLS.
PACOfficial partnership.
Athletech News"HomePlunge Wants To Solve Hotels' Cold Plunge Problem," September 2026.
How a pilot works

One suite. Real guest feedback. Then decide.

i.

Choose the suite

Usually the most wellness-positioned room you have. The unit arrives fully assembled.

ii.

Set up in five minutes

Housekeeping or engineering connects two hoses and plugs it in. No contractor, no permit.

iii.

Measure for 60 days

Guest comments, rate premium, booking notes. Add rooms only if the numbers say so.

The journal

Planning notes for operators.

All articles
01

Adding cold plunge to a room without plumbing

The options when a renovation is off the table, and what each asks of the room.

→ 02

The cost of in-suite cold plunge

Unit price, installation and running costs, set out for a budget line.

→ 03

Comparing hotel cold plunge options

Built-in, portable and in-tub, side by side on cost, timeline and guest experience.

→ 04

Turning an existing bathtub into a cold plunge

Retrofitting the tubs a property already has: steps, costs and timelines.

→
Questions

The details.

Anything not covered here, ask on a call. A real person in the USA answers, usually the same day.

What does installation involve?

The unit arrives fully assembled. Two insulated hoses connect to the existing bathtub and the unit plugs into a standard outlet. Under five minutes, no plumber, no contractor, no permit.

How cold, and how is it controlled?

Precise control down to 34°F. Scheduling and temperature are managed from a phone app, so the spa or front desk can prepare a session before the guest returns to the room.

Can the room be turned between guests?

Yes, and this is usually the deciding question. The H3 takes tap water to 50°F in about 30 minutes and to 34°F in about an hour and twenty minutes. Housekeeping drains after checkout on their normal pass, and the room can be cold before the next guest reaches it.

Whose water is the guest sitting in?

Their own. The tub drains after each guest like any bathtub on the floor, so every stay starts with fresh water. The reusable filter keeps a single guest's water clear across sessions during their stay, and rinses every 4 to 6 weeks.

What is the housekeeping load?

Drain the tub after each guest, the same way the team already handles a bathtub. Fresh water every stay. No chemicals program, no consumables.

Can we see it running first?

If you are in South Florida, yes. The installation at Carillon Miami Wellness Resort is live, and we arrange walkthroughs for hotel and spa operators. Ask on the call or by email.

Can we pilot one room first?

That is how every hotel engagement starts: one unit, one suite, validate guest response, then scale. Multi-unit pricing is discussed after the pilot proves demand.

Begin

See if it fits your property.

Fifteen minutes on suite selection, pilot structure and pricing, with a Carillon walkthrough if you are local.

Book a 15-minute call Email us instead

Send your property, your questions and your timeline to [email protected]. A real person in the USA answers.