How to protect your smartphone from heat? Our advice for the summer

The thermometer exceeded 40 degrees in France for the second time in less than a month. This new heatwave episode puts the electronic components of our devices to the test. Indispensable, smartphones are on the front line and do not tolerate extreme temperatures well, whether it is hot weather or when the mercury drops below zero degrees.

Unlike desktop and laptop computers or game consoles which are equipped with a fan to evacuate heat, smartphones most often have a passive cooling system. Less effective, it does not directly cool the device, which is therefore dependent on the ambient air. When conditions are normal, the smartphone takes advantage of the situation to regulate itself and allow its owner to take advantage of all the features.

In periods of high temperatures or heat waves, the chips that equip our mobile devices are severely abused. And this, even if the manufacturers take into account the most extreme conditions during their tests.

How are smartphones tested by brands?

All brands adopt more or less similar testing procedures. A few months ago, we were able to approach Oppo's main factory in China to find out how the manufacturer tests the solidity of its smartphones.

The Chinese brand also returned to the tests carried out in its laboratories and is particularly interested in extreme temperatures. “We place the phones in an extremely high temperature environment of 85℃ for 500 hours. After the test, the functions should be normal,” says Oppo.

These temperature tests are carried out by all manufacturers, in particular at Apple. The Independent site recently unveiled details of how the American giant will proceed. The British daily ensures that the Cupertino company tests its chips at temperatures between -40 ° C and 110 ° C.

In use, smartphones do not like when the outside temperature exceeds 35 degrees.

What are smartphones supposed to withstand?

Manufacturers recommend a range of operating temperatures between 0°C and 35°C. Regarding the storage of the smartphone, the temperature range oscillates between -20 ° C and 45 ° C. This information is sometimes specified on the technical sheet of the device, the manufacturer's website or in the instructions for use. Apple devotes a section to this question on its site and explains that you must use your iOS device "in a place where the temperature is between 0 and 35 ºC" and keep it in a place "where the temperature is between -20 ºC and 45 ºC”.

With many manufacturers, it will be necessary to turn to the instructions for use or the safety instructions. For its Galaxy S10, Samsung indicates that “the device can be used in an environment where the ambient temperature is between 0°C and 35°C”. The smartphone can be stored “at an ambient temperature between -20°C and 50°C”.

The two market giants are not the only ones to communicate. We find very similar temperatures at OnePlus. The latest model of the Chinese brand, the OnePlus 7, assures in its user manual that “the ideal operating temperatures are from 0°C to 35°C, the ideal storage temperatures are from -20°C to +45°C ".

Note that there are also rugged smartphones like the Galaxy Xcover 4s. These models will be able to withstand more difficult conditions such as temperatures of -51 to 71 degrees, rain, sand or dust. An IPxx or MIL-STD-810G certification then certifies it.

What are the risks if you do not follow the manufacturers' recommendations?

Smartphones – and their chips – don't like heat and react when they get too hot. Around 40°C, they can show signs: a screen that goes black, (fast) or wireless charging that slows down or stops. Performance can be reduced and if this is not enough, they can go into safety mode while waiting to find a more reasonable temperature. For example, iPhone owners may see the alert message “Temperature: your iPhone needs to cool down”. Other brands display similar messages.

Having to do without your smartphone can be penalizing, but these features are designed to prevent excessive overheating. They also prevent the user from running a risk. The smartphone is certainly not going to explode due to heat and if cases exist, they are the result of design or battery problems. Samsung faced such an issue when it released its Galaxy Note 7 and has since tightened its security tests. However, the heat can cause irreversible damage to the mobile. Using or storing the device outside the recommended temperature ranges may damage the screen, the entire device, or reduce – temporarily or permanently – battery life.

Note that this file only discusses problems related to extreme temperatures. Drops or exposing a smartphone to splashes, water or dust can also seriously damage it.

Tips: the right things to do to avoid overheating

To avoid having your smartphone stop, reduce its performance or irreparably damage its components, a few rules apply. With a minimum of common sense and caution, it will indeed be possible to reduce the risks. First of all, keep in mind that receiving an alert is not serious in itself. You just have to wait for the temperature to drop inside to regain use.

A few tips: when the smartphone is used

Lithium-ion batteries do not like high heat and can quickly rise in temperature when the device is used. It is therefore necessary to avoid keeping the smartphone exposed to the sun or another source of heat. The screen is also a fragile element that does not like the sun's rays or high temperatures. The touch screen may become unstable and stains may appear. Care should therefore be taken to keep it out of the sun's rays to avoid "heat stroke" and to limit its use.

If the damage can – in the short term – be less visible than on the screen, the internal components are not spared. The battery or processor may be overheating. The first advice is therefore to limit its use and avoid soliciting – as far as possible – your device.

It is more precisely not recommended to use greedy applications (games, videos, etc.) in the event of strong heat as well as to use the GPS, in particular requested when you use a guidance application (Maps, Waze) in your car. The 3G/4G function also tends to raise the mercury in the event of heavy use. It is possible to take a look in the settings of your smartphone (iOS or Android) and deactivate functions such as Wi-Fi, GPS, Bluetooth or mobile data. In addition to relieving the battery, this prevents the device from heating up.

Finally, it is better to avoid using your smartphone while it is charging. This phenomenon will cause excessive heating that can damage the device, especially during heat waves. Avoid a confined space and prefer a location in the shade to charge your device (smartphone, tablet, computer, etc.).

Some tips: when the smartphone is idle

Even when not in use, the smartphone can be subject to a "heat stroke". Care should be taken not to expose it in sensitive places, such as behind glass or inside a car. You can also turn the device over so as not to expose the screen to direct sunlight for a long time.

Also avoid placing your mobile on a surface that itself tends to heat up. It is also possible to remove the shell of the smartphone to promote heat dissipation. Finally, you can activate your smartphone's airplane mode to avoid gaining unnecessary degrees (network search) and preserve its battery.

It is best not to use applications that allow you to know the temperature of the components of your mobile, especially in periods of high heat. Indeed, they solicit the smartphone to provide this same information and accentuate the phenomenon.

Last reminder, do not place your phone in a refrigerator or in water, even if it is certified IP67/68 (water resistant). Indeed, this action risks creating a thermal shock that can permanently damage your device.