The short answer is: technically yes, but it is strongly not recommended. A sauna environment — whether traditional Finnish-style or infrared — exposes your phone to conditions it simply is not designed to handle, and the damage that results is often permanent.

Every major smartphone manufacturer publishes operating temperature limits for their devices. Apple, Samsung, and Google all specify a maximum safe operating temperature of around 35°C (95°F). Traditional saunas typically run between 65°C and 90°C (150°F–195°F). Infrared saunas operate at lower temperatures — usually 49°C to 60°C (120°F–140°F) — but still exceed the safe limit for most devices. Even a single session at these temperatures can cause cumulative damage that shows up weeks later as a swollen battery, a failing screen, or a phone that simply will not turn on.

Here is a full breakdown of what actually happens, and what to do instead.

Key Takeaways

Most smartphones are rated to operate safely only up to 35°C (95°F) — well below sauna temperatures of 65°C–90°C (150°F–195°F).
Traditional saunas pose the highest risk due to the combination of extreme heat and steam humidity.
Infrared saunas are cooler but still exceed safe operating thresholds for most devices.
Lithium-ion batteries degrade rapidly above 45°C (113°F) and can swell or rupture at extreme temperatures.
IP water-resistance ratings do not apply to steam — sauna conditions degrade the waterproof seals themselves.
Even if your phone survives a sauna session visually, cumulative internal damage builds over multiple exposures.
Waterproof Bluetooth speakers placed outside the sauna, or a simple timer, are practical alternatives.
Taking your phone into a sauna typically voids the manufacturer’s warranty.

Why Saunas Are Harmful to Smartphones

The Heat Problem

Lithium-ion batteries — the type in every modern smartphone — begin degrading rapidly when exposed to sustained temperatures above 45°C (113°F). At sauna temperatures, this degradation accelerates dramatically. The battery can swell from the buildup of internal gases, physically pushing against the screen and back panel. In extreme cases, this swelling can rupture the battery and create a fire risk. Even below the rupture threshold, heat permanently reduces battery capacity — a phone that comes out of a sauna visually intact may have lost a meaningful percentage of its total battery life.

Beyond the battery, screen adhesives soften at high temperatures, which can cause the display to separate from the chassis. Solder points on internal circuit boards can weaken. Processors will throttle aggressively and may shut the phone down entirely as a protective measure — but shutdown does not prevent damage at extreme temperatures, it just limits how quickly it occurs.

The Humidity Problem

Traditional saunas generate significant steam, and this is an entirely separate category of risk from heat alone. Many people assume that a phone with an IP67 or IP68 water-resistance rating is protected from sauna humidity. It is not, for two reasons. First, IP ratings measure resistance to liquid water under controlled conditions — typically submersion at room temperature — not steam. Steam penetrates seals more easily than liquid water. Second, sauna heat degrades the adhesive gaskets that provide water resistance in the first place. A phone that is water-resistant at room temperature may not be after it has been repeatedly heated in a sauna.

Infrared Saunas: Safer, But Not Safe

Infrared saunas run cooler than traditional ones and produce less humidity, which reduces — but does not eliminate — the risk. At 49°C to 60°C, you are still operating your phone well above its rated limit. The lower humidity means moisture damage is less of an immediate concern, but thermal damage to the battery and screen components is still occurring. If you use an infrared sauna regularly and bring your phone in each time, the cumulative damage adds up even if no single session causes obvious failure.

What Actually Happens Step by Step

When you bring your phone into a sauna, this is the sequence of events happening inside the device:

Battery chemistry accelerates: Heat speeds up the chemical reactions inside lithium-ion cells, causing faster degradation and capacity loss with every session.
Internal components expand: Different materials expand at different rates in high heat, stressing the connections and solder points that hold the phone together internally.
Screen adhesive softens: The glue holding the display assembly together begins to lose integrity, which over time causes screen separation or dead spots.
Moisture intrudes: In traditional or steam saunas, humidity penetrates around degraded seals and condenses inside the device as it cools, corroding circuit board connectors over time.
Processor throttles or shuts down: The phone detects overheating and either limits performance severely or forces a shutdown — but not before thermal stress has been applied to its components.

Practical Alternatives to Bringing Your Phone Into the Sauna

The most common reasons people want their phone in the sauna are music, podcasts, timing sessions, and staying reachable. All of these have solutions that do not involve risking your device:

Waterproof Bluetooth speaker placed outside the sauna: Pair it before you go in, start your playlist, and leave the speaker just outside the door. You get the audio without any device exposure to heat or steam.
Dedicated sauna timer: A simple physical timer or a sauna-specific app loaded before you enter means you do not need the phone inside at all.
Leave it in a locker or changing room: The sauna is one of the few remaining contexts where being genuinely unreachable for 20–30 minutes is entirely socially acceptable. Most people find that once they adjust to it, phone-free sessions are significantly more relaxing.
Some smartwatches tolerate heat better: Check your specific model’s thermal rating. Some are designed for more extreme environments than smartphones. Even so, prolonged sauna exposure is not ideal for most wearables either.

What If Your Phone Gets Overheated in a Sauna?

If you have taken your phone into a sauna and it has shut down or is showing a temperature warning, follow these steps:

Do not force a restart immediately. Let it cool gradually at room temperature — avoid placing it in a fridge or freezer, as rapid temperature change causes condensation that can damage internal components.
Once it returns to room temperature, power it on and check for visual issues: screen separation, unresponsive areas, or distorted display.
Monitor battery behaviour over the following days — unusual drain or failure to charge to full capacity suggests the battery sustained heat damage.
If the phone behaves abnormally, take it to a repair service sooner rather than later. Swollen batteries in particular are a safety issue and should be replaced promptly.

Final Thoughts

A sauna session is one of the better things you can do for recovery, relaxation, and general wellbeing. Bringing your phone in undermines both the phone and the session — most people find they get significantly more out of the experience when they are fully disconnected. The phone-free approach is also the one that does not end with a warranty claim or a battery replacement.

Leave it outside, use a Bluetooth speaker if you want audio, and let the sauna do what it is actually good at. If you are interested in the broader intersection of heat therapy and skin health, our article on red light therapy and tanning covers how different types of heat and light treatment interact with the skin.

Frequently Asked Questions

Can I bring my phone in a sauna for 10 minutes?

Even 10 minutes at traditional sauna temperatures exposes your phone to well above its rated operating limit. The damage may not be immediately obvious, but thermal stress builds cumulatively. The recommendation from all major manufacturers is to avoid it entirely.

Will my iPhone be okay in a sauna?

Apple specifies a maximum operating temperature of 35°C (95°F) for all iPhone models. Traditional saunas run at 65°C–90°C. Even in an infrared sauna at 50°C–60°C, your iPhone is outside its safe operating range. Apple’s warranty explicitly excludes damage from exposure to extreme temperatures.

Is an infrared sauna safer for phones than a traditional sauna?

Somewhat — lower temperatures and less humidity reduce immediate risk. But infrared sauna temperatures still exceed the safe operating limit for most smartphones, and repeated exposure causes cumulative damage over time.

Can I wear AirPods in the sauna?

AirPods are not rated for sauna conditions. The heat degrades their battery significantly faster than normal use, and moisture penetrates the internals. A waterproof Bluetooth speaker placed outside the sauna is a much better alternative for audio.

Does a waterproof phone rating protect it in a sauna?

No. IP water-resistance ratings apply to liquid water submersion at controlled temperatures, not steam. Sauna heat also degrades the adhesive seals that provide water resistance, making IP-rated phones increasingly vulnerable with each session.

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

Let it cool slowly at room temperature before powering it on. Do not use a freezer or fridge. Once cooled, check for screen issues and monitor battery performance over the following days. A noticeably swollen battery should be replaced promptly for safety reasons.

Research Sources

Apple, Samsung, and Google all specify maximum safe operating temperatures of 35°C (95°F) for their smartphone devices, well below typical sauna temperatures of 65°C–90°C. Lithium-ion batteries experience accelerated chemical degradation and capacity loss at sustained temperatures above 45°C (113°F), with swelling and rupture risk increasing at higher temperatures. IP water-resistance ratings apply to liquid water under controlled conditions and do not protect against steam penetration or the degradation of adhesive seals caused by repeated heat exposure in sauna environments.

Can You Take Your Phone in a Sauna? (The Real Risks)