As of 2023, roughly 98 percent of adults aged 16 to 24 in the UK own a smartphone, and around 80 percent of the older population (those aged 65 and over) do as well.

Globally, there are around 7.2 billion mobile phones in use, helping people with everything from navigating exciting journeys to growing a business.

Screen time varies by age group, but users between 16 and 64 are estimated to spend about six hours and 35 minutes a day on their devices, according to The Independent.

Given the high level of daily usage, it’s understandable why some people opt to charge their iPhones overnight to have a full battery for the next day.

However, Apple has issued a caution for iPhone users who do this, urging them to “use their common sense.”

In the “Important safety information for iPhone” memo on Apple’s website, the company advises mobile phone users to “avoid prolonged skin contact with the charging cable and connector when the charging cable is connected to a power source.”

This is due to the potential for physical injury or discomfort while users are asleep.

Additionally, Apple warns against sleeping or sitting on the charging cable or connector, noting that “sustained contact with warm surfaces for long periods of time may cause discomfort or injury.”

The memo advises, “Use common sense to avoid situations where your skin is in contact with a device, its power adapter, or a wireless charger when it’s operating or connected to a power source for long periods of time.”

It also recommends, “Keep your iPhone, the power adapter, and any wireless charger in a well-ventilated area when in use or charging. Take special care if you have a physical condition that affects your ability to detect heat against the body.”

Although these warnings are widely known, many people still opt to sleep while their phones are charging.

In line with Apple’s advice, a firefighter from Kent Fire Rescue recently posted a video on TikTok, saying: “We get a lot of questions here at Kent Fire Rescue about why you shouldn’t charge phones overnight. So here are the reasons why.”

“First: You can’t smell anything when you’re asleep, so if a fire starts, it won’t wake you up.

“Second: It only takes three breaths, right, to knock you unconscious.

“Third: Many people use cheap or faulty phone chargers, and even genuine ones have been known to start fires.”

In a video shared on social media, he recommended that it is ‘much safer’ to charge your phone while you are awake and present.