How to Hydrate Around an Infrared Sauna Session

That deep, steady sweat is the whole point of an infrared sauna. It's also the part most people forget to plan for. Every drop that beads up and rolls off is fluid leaving your body, and if you don't put some of it back, you can walk out feeling more wrung-out than refreshed. Good infrared sauna hydration isn't complicated, but it does take a little forethought, especially here in East Bethel and the North Metro, where dry winter air pulls moisture out of you long before you ever sit down in the heat.

So let's keep it practical. Here's what's actually happening when you sweat, what to drink before, during, and after, when plain water is enough versus when electrolytes earn their place, and the warning signs that mean it's time to step out and cool down.

Why You Sweat (and Lose Fluid) in an Infrared Sauna

Infrared saunas work differently from the old hot-rock kind. Rather than heating the air around you to scorching temperatures, they use infrared warmth to heat your body directly, which is why they run cooler, usually around 110 to 135°F. If you've ever wondered how hot an infrared sauna actually gets, that lower number tends to surprise people. It feels gentler than a traditional sauna. But make no mistake: you still work up a genuine sweat.

Here's the mechanism. When your core warms up, your body pushes more blood toward the skin and switches on your sweat glands to cool you down. That sweat is mostly water, and producing it pulls fluid out of circulation. Researchers describe this as the body firing up its cooling systems under heat stress, with sweating front and center as the way you shed heat and hold a steady temperature. That same review points out that rehydrating before, during, and after a session is a recognized part of using a sauna sensibly.

None of this makes infrared saunas risky. It just means dehydration is the thing worth managing, mostly because it's so easy to under-drink without noticing. A comfortable session doesn't feel like exercise, so people skip the water bottle and pay for it later with a headache.

Before You Step In: Pre-Hydration

The best time to start hydrating is before you ever open the sauna door. Walk in already thirsty and you're behind from the first minute. Aim for a glass or two of water in the hour or two beforehand. For activity in the heat, Cleveland Clinic suggests drinking roughly 16 to 20 ounces of fluid one to two hours ahead and checking the color of your urine, pale or straw-colored means you're in good shape, while dark yellow is your cue to drink before you go in.

Two things to go easy on beforehand: alcohol and a lot of caffeine. Both tend to pull water out of you, which is exactly backwards from what you want walking into a heat session. Save the coffee for a smaller cup earlier in the day, and hold off on the wine until well after.

It also helps to simply bring water in with you. If you're still sorting out your routine, our guide on what to bring to your first session covers the essentials, and a bottle of water tops the list. When you book our infrared sauna at 5D Wellness, plan to have something to sip within arm's reach.

During and After: Replacing What You Sweat

Inside the sauna, keep it simple. Take small, steady sips rather than gulping, and pay attention to how you feel. The heat should feel pleasant, not punishing. If you start to feel lightheaded or queasy, that's your signal to step out early, not a hurdle to push through.

The finish line is where a lot of people stop drinking, and that's a mistake. Thirst lags behind what your body actually needs, so one glass at the end rarely closes the gap. Keep a bottle going for the next hour or two. A little food helps too: a banana, some avocado, leafy greens, a handful of nuts, or a lightly salted snack all bring back minerals you sweated out. A cool shower afterward feels great and nudges your body back toward its normal temperature before you head out into the Minnesota air.

Water vs. Electrolytes: When Plain Water Isn't Enough

For a short, comfortable session, plain water usually does the job. Still, it's worth knowing why water alone sometimes falls short. When researchers let people drink only as much as thirst dictated during heat and exercise, they replaced just about 41% of the fluid they'd lost and still finished mildly dehydrated. Drinking to thirst, in other words, tends to leave you a little short.

Part of the reason is that sweat isn't pure water. It carries sodium and chloride along with smaller amounts of other minerals, which is why heavy or repeated sweating draws down your electrolytes, not just your fluid. Put a little sodium back and your body actually holds on to the water you drink instead of passing it straight through. That same hydration research found that for cool, ordinary conditions a basic electrolyte drink is plenty, with fancier custom mixes only mattering for serious heat and hard effort.

So here's a rule of thumb you can actually use. For a single, comfortable session, reach for water. If you've sweated hard, stacked back-to-back sessions, or you notice cramping or a lingering headache afterward, add electrolytes, whether that's a sports drink, an electrolyte tablet, or simply some salty food alongside your water.

The Minnesota Angle: Hydration Through the Seasons

Hydration around the sauna shifts a little with the calendar up here. In the depths of a Minnesota winter, furnace heat and bone-dry indoor air are already quietly pulling moisture out of you all day. Add a sauna on top and it's easy to end up short, even though you never felt overheated. Winter is exactly when it pays to be deliberate about drinking, and to think about how often you use the sauna so your hydration keeps pace with your routine.

Come allergy season and summer, the math flips. After a hot afternoon of yard work in Ham Lake, a round of pickleball in Andover, or a lake day out around Blaine, Cedar, or Anoka, you may walk into your session already a quart low. On those days, hydrate generously beforehand and lean toward electrolytes afterward. Whatever the season, the goal holds: come in topped up, sip through, and replace what you lose.

Frequently Asked Questions

Should I drink water before or after an infrared sauna?

Both. Arrive already hydrated with a glass or two of water in the hour or two beforehand, sip during your session, and keep drinking afterward to replace what you sweated out. Treating hydration as a before-during-after habit, rather than one big glass at the end, keeps you feeling steady.

Do I need electrolytes, or is plain water enough for an infrared sauna?

For a short, comfortable session, plain water is usually fine. If you sweat heavily, do back-to-back sessions, or feel a little crampy or lightheaded afterward, adding electrolytes like sodium and potassium helps your body hold on to the fluid you drink. Electrolyte-rich foods such as a banana, avocado, or a salty snack work too.

How much water should I drink around a session?

There's no single magic number, but a practical starting point is a glass or two before, small sips during, and another glass or two after. A simple check: your urine should be pale or straw-colored. If it's dark yellow, you need more fluid.

What are the warning signs I'm getting dehydrated in the sauna?

Dizziness, lightheadedness, nausea, headache, a racing heartbeat, or feeling unusually weak are all signs to step out, cool down, and drink. Don't try to tough it out, end the session early and rehydrate.

The Bottom Line

Hydrating around an infrared sauna really comes down to four small habits: top up before, sip during, replace after, and add electrolytes when you've sweated hard. Build those into your routine and the sauna gives back exactly what you're after, that loose, refreshed, well-rested feeling, without the headache that comes from running on empty. When you're ready, book a session with us here in East Bethel, bring your water bottle, and enjoy the heat the easy way.

This article is for general wellness and educational purposes only and is not medical advice. 5D Wellness services are not a substitute for professional medical care. Results vary by individual. Consult a qualified healthcare provider before starting any new wellness practice, especially if you are pregnant or have a medical condition.