Free cold plunge and sauna tools
How cold, how long, and how hot?
Get a session length for your water temperature and experience, build a weekly sauna and cold routine against published targets, and read guides that show their sources. Free, in your browser, no sign-up.
Free toolsNo sign-upSources on every number
50 F water
- MonCold plunge2:0050 F
- WedSauna15:00180 F
- FriContrast, 3 rounds27:00end cold
A demo of the app's session screen, running fast. Tap to pause.
of cold water a week, in 2 to 3 sessions, logged by the winter swimmers in the 2021 Soberg study (Cell Reports Medicine).
57 minof sauna a week in the same study group, split across visits. A target, not a prescription.
50 to 59 Fis the beginner water range Cleveland Clinic suggests, for a minute or two, never below 40 F.
Free tools
Two free tools that answer the first two questions
How long should I stay in, and what should my week look like? Both tools show their math and their sources, run in your browser, and never ask for an account.
Start hereCold plunge time calculator
Enter your water temperature, your experience and your goal. Get a session length in minutes, a weekly cold-minutes target, the warning thresholds for your temperature band, and a plain stop-if list.
Get my plunge time
PrintableContrast therapy builder
Pick sauna minutes, cold minutes, rounds and the order. It lays out each session on a timeline, totals your week against the 57 minutes heat and 11 minutes cold targets, and adds the rest and rehydration line.
Build my routineHow the app will work
Time it, log it, see your week fill up
The PlungeLog app is a timer and a log for people who already have a tub, a barrel, a chest freezer or a gym sauna. It never controls hardware.
- 1
Start the timer
Pick cold or heat, enter the water or air temperature, and press go. Rounds and a breath timer are built in; the screen stays readable with wet hands.
- 2
Log the session
Minutes, temperature, rounds and how you felt are saved the moment you stop, with an optional sync to Health Connect or Apple Health.
- 3
Watch the week fill up
A weekly heat and cold target built on published protocols shows how much of it you have done, plus a streak that forgives a rest day.
The honest bit
What this site is, and what it is not
This site is
- Session lengths, temperatures and weekly targets taken from published studies and safety bodies, with the source named next to the number.
- Honest about the evidence: small studies, mostly men, mostly short. We say so every time.
- Safety first on every page: cold shock, cardiac risk, never alone, never after alcohol, no breath-holds in water, hypothermia signs, sauna dehydration.
- Independent. Nobody pays to be recommended, and any price on the site says when it was checked.
This site is not
- Medical advice. Nothing here diagnoses or treats anything, and no routine is right for everyone.
- A promise of outcomes. Cold and heat do not cure, burn fat on their own, or fix sleep or mood for sure.
- A hardware controller. The tools and the app time and log; they never set your chiller or your heater.
- A reason to skip the doctor. Heart conditions, high blood pressure or its medication, pregnancy, Raynaud's and poor circulation all mean a conversation first.
Every guide ends with the pages its facts came from. If a number is not sourced, we do not print it.
From the guides
Guides that show their sources
contrast therapy
Sauna and Cold Plunge: The Right Order and a Weekly Routine
Questions
Good questions, straight answers
Is PlungeLog free?
The cold plunge time calculator and the contrast therapy builder are free, with no account. The PlungeLog app is in development; early-access members hear about it first.
How cold should a cold plunge be?
Cleveland Clinic suggests 50 to 59 F for beginners and not going below 40 F. Cold shock peaks between 50 and 60 F for people who are not used to it, so colder is not better: shorter is. The cold plunge time calculator turns your temperature into minutes.
How long should I stay in?
A minute or two to start, and Cleveland Clinic puts the ceiling at five minutes. The winter swimmers in the 2021 Soberg study averaged about 11 minutes of cold water a week across 2 to 3 sessions. Get out early if you feel lightheaded, numb or confused.
Sauna first or cold plunge first?
Most routines warm up first and end on cold, the pattern the Soberg study group followed. Ending on heat is gentler if you have trouble rewarming. The contrast therapy builder lays out either order and totals your week.
Who should not cold plunge?
Cold water spikes heart rate and blood pressure in the first minute or two. Talk to your doctor first if you have a heart condition, high blood pressure or take medication for it, are pregnant, or have Raynaud's, peripheral neuropathy or poor circulation. Never plunge alone or after alcohol.
Does the app control my chiller or sauna heater?
No. PlungeLog times and logs sessions and keeps your weekly targets and streaks. It never connects to or controls hardware.
Is PlungeLog affiliated with a tub, sauna or app brand?
No. PlungeLog is an independent project by Viral Labs and is not affiliated with any tub, sauna, chiller or app brand. When we name one, we say so on the page.