Can You Bring Your Phone in a Sauna?

Short answer: you physically can carry your phone into a sauna, but you should not. Apple and Samsung both rate their phones for use at up to 95°F (35°C) — and even a cooler infrared sauna runs well above that, at roughly 110–150°F. Traditional saunas run hotter still, around 150–195°F. In other words, every common sauna type exceeds the temperature your phone is designed for, and using one in very hot conditions can permanently shorten battery life. Leave the phone outside the cabin.

The numbers: phone limits vs sauna temperatures

The mismatch is not close, which is why this is a clear-cut answer rather than a judgment call:

• Phones: Apple designs iPhones for use where the ambient temperature is between 32°F and 95°F (0°C to 35°C), and for storage between -20°C and 45°C (-4°F to 113°F). Samsung gives the same 32–95°F range as the optimal usage temperature for Galaxy phones, and warns that continuous use or charging in extreme temperatures may accelerate battery deterioration.
• Infrared saunas: roughly 110–150°F — cooler than a traditional sauna, but still 15 degrees or more above a phone's 95°F operating limit.
• Traditional saunas: roughly 150–195°F — nearly double to more than double the phone's 35°C operating limit in Celsius terms, and well above even its 113°F storage limit.

That last point matters: a phone does not have to be switched on and in use to be at risk. Even sitting turned off on a bench, it is stored in an environment hotter than its rated storage range. Browse infrared saunas → Browse traditional saunas →

What sauna heat actually does to your phone

Heat affects a phone in stages, and the phone itself will tell you it is unhappy before it fails outright:

• Battery life, permanently. This is the best-documented risk, straight from the manufacturers. Apple states that using an iOS device in very hot conditions can permanently shorten battery life; Samsung warns that continuous use or charging at temperature extremes may accelerate battery deterioration and lead to unexpected shutdowns and shorter battery life. Heat speeds up the chemical reactions inside a lithium-ion battery, and that wear does not reverse when the phone cools down.
• Throttling, then shutdown. When a phone gets too warm, it protects itself: the screen may dim, performance may slow, charging may slow or stop, and some features may be temporarily disabled. In extreme conditions Apple says the device may show a temperature warning and become temporarily disabled until it cools. A shutdown is a safety feature, not proof that no harm was done — the battery wear from the heat exposure has already happened.
• Seals, screens, and adhesives under stress. A phone is held together with adhesives and seals that are not designed for sustained high heat. Repeated heat exposure can stress those seals and the screen assembly, and can make the phone more vulnerable to moisture later — even if it looks fine the day after a sauna session.
• Humidity and steam make it worse. Traditional saunas and especially steam rooms add moisture to the heat. Water-resistance ratings are tested with fresh water at room temperature, not with hot steam, so a water-resistant rating does not make a phone steam-safe. Moisture that gets in can also condense inside the phone as it cools.

Medical disclaimer: This article is for informational purposes only and is not medical advice. The studies cited describe associations found in research — not proof that sauna use causes the reported outcomes. Sauna sessions involve intense heat and dehydration; check with a healthcare professional before starting a routine, especially if you have a cardiovascular condition, are pregnant, or take medication that affects heat tolerance.

Infrared vs traditional vs steam room: is any of them safe?

No — but they are not equally bad:

• Infrared sauna (110–150°F): the lowest-heat option, and the one that tempts people most, because it feels gentler. It is still above the 95°F phone limit for the whole session, so the battery and heat risks still apply. The lower temperature is not a safe zone; it is just a slower version of the same problem.
• Traditional sauna (150–195°F): the highest dry-heat risk, plus humidity when water is poured on the stones. This is the worst dry-heat case for a phone.
• Steam room: the worst overall combination — sustained heat plus near-constant moisture. If a phone should not go in a sauna, it definitely should not go in a steam room.

For the session itself, see our how to use an infrared sauna guide → and our infrared sauna safety guide →

Does a waterproof case or a towel help?

No. A waterproof case protects against splashes of room-temperature water; it does nothing about heat, and it can actually trap heat around the phone. Wrapping the phone in a towel has the same problem in reverse: insulation slows heat getting in, but it also slows heat getting out, and over the course of a session the phone still ends up hot. Neither workaround brings a sauna inside the phone's rated temperature range, so neither makes the session safe for the device.

What to do if your phone already went in the sauna

• Let it cool gradually at room temperature. Do not put it in a fridge or freezer and do not run it under cold water — a sudden temperature change can cause condensation inside the phone. Samsung's guidance after temperature extremes is the same principle: let the device return to its normal operating range before use.
• Do not charge it while it is hot. Wait until it is back to room temperature before plugging it in. Charging adds its own heat, and both manufacturers limit or stop charging when a device is outside its safe temperature range.
• Watch for warning signs over the following days. Faster battery drain, unexpected shutdowns, a screen that behaves oddly, or a battery that looks swollen are all reasons to stop using the phone and get it checked rather than keep using it and hoping the problem goes away.

What to use instead of your phone in the sauna

Almost everything people want a phone for in a sauna has a heat-proof alternative:

• Timing your session: use the cabin's built-in timer, or a simple sand timer. Sauna cabins have built-in timers for a reason, and a sand timer needs no battery and does not care about heat.
• Music or a podcast: put a Bluetooth speaker just outside the cabin door, with the phone outside with it. You get the audio without putting the phone in the heat.
• Reading: leave the phone outside and bring a book or magazine instead — paper has no battery to degrade.

The sauna session itself works better without the phone, too: the point of the session is a break, and a phone-free session is part of that. Our infrared sauna accessories guide → covers the extras worth having in and around the cabin, and the home sauna buying guide → walks through choosing the cabin itself.

FAQs

Can you bring your phone in a sauna?

Physically yes, but you should not. Sauna temperatures exceed the 95°F operating limit that Apple and Samsung specify for their phones, and heat in that range can permanently shorten battery life.

Can I bring my phone into an infrared sauna if it runs cooler?

Still no. Infrared saunas run roughly 110–150°F, which is still above the 95°F limit for the whole session. Cooler than a traditional sauna does not mean safe for a phone.

Will one sauna session ruin my phone?

Not necessarily — many phones survive a single session and look fine afterwards. But the battery wear from heat exposure is cumulative and does not reverse, so repeated sessions add up even when no single session causes an obvious failure.

Does a waterproof case protect my phone in a sauna?

No. Water-resistance is tested with room-temperature water, not hot steam, and a case does nothing about heat — it can trap heat around the phone instead.

Can I take my phone into a steam room?

No — a steam room is the worst case, combining sustained heat with near-constant moisture.

What should I do if my phone overheated in a sauna?

Let it cool gradually at room temperature, do not charge it until it is back to room temperature, and do not chill it rapidly in a fridge or under cold water. If it shows faster drain, unexpected shutdowns, or a swollen battery afterwards, stop using it and get it checked.