Whether it’s early morning jogs, lunchtime walks or perspiring on a train or the tube – summer’s the season of sweating. Unlike other watches, if you own a smartwatch you will probably wear it all day and night, in the office, as you sleep, as you cook and in the gym – as it monitors your heartbeat and calories burned. 

But have you ever stopped to think about what else your smartwatch is collecting during these hot, active months? Now experts commissioned by MattressNextDay have swabbed a range of smartwatches and tested them in a lab.

 

And the results were as eye-catching as stomach-churning as 70 per cent were found to contain one shocking variety of bacteria ‘superbug’ – Pseudomonas aeruginosa. 

This bacterium – found in cockroach droppings, soil and water – is known for its resilience and ability to thrive in warm, moist environments. 

It’s also a notorious inhabitant of warm, damp environments, such as your sweaty smartwatch band and worryingly it can survive on surfaces for days, even weeks, and is resistance to many common cleaning agents. 

For most healthy people, Pseudomonas aeruginosa can cause mild skin irritation or rashes. But if you have sensitive skin, eczema, or even a tiny cut on your wrist, this bacteria can cause more serious infections. 

In rare cases, it can even lead to folliculitis (painful, inflamed hair follicles) or more severe skin conditions. For anyone with a weakened immune system, the risks are even higher. 

What’s truly alarming is that the bacteria doesn’t just stay on your watch. If you wear your smartwatch to bed, which many do to track their sleep, you’re bringing that bacteria into direct contact with your sheets and pillowcases. 

Over time, your bedding can become a secondary home for these germs, increasing your risk of skin problems and potentially even respiratory issues if bacteria become airborne. 

MattressNextDay’s sleep expert Martin Seeley said: “According to the result the swab report it shows, your smartwatch could be tracking more than just your steps or sleep – it might be carrying a whole hidden world of bacteria, especially during the sweaty summer months. 

“With this in mind, cleaning your smartwatch regularly should become as automatic as checking your notifications. It’s a simple step that can make a big difference to your skin, your sleep, and your overall health.”

Why summer is the worst season for smartwatch hygiene: 

It’s no secret that we sweat more in summer. But what does that mean for your smartwatch? Sweat isn’t just salty water – it’s a cocktail of oils, dead skin cells, and proteins. When it gets onto your smartwatch band, it creates a sticky, damp environment that helps bacteria thrive. 

The problem is, most people rarely, if ever, clean their smartwatches. 

Surveying 575 smartwatch owners they found almost three quarters had never cleaned their device, not even after a sweaty run or a dip in the pool. Of those who have cleaned their device, only 10 per cent clean it once a year. 

Unlike your gym clothes, which get tossed in the wash after every use, your smartwatch just keeps going, day after day, growing grimier with each summer adventure. 

And it’s not just the band. The tiny crevices around the watch face, the clasp, and the sensors are perfect hiding spots for bacteria. In the heat, these areas stay warm and moist for hours, allowing bacteria to multiply. 

How suncream, sweat and showers can make your smartwatch even more dirty this summer: 

In summer, people are more likely to carry out outdoor activities such as hiking, swimming, or playing sports. All of this results in more dirt, dust, and bacteria coming into contact with your skin and your watch. 

Even suncream and insect repellent, while protecting you from the elements, can mix with sweat to create a sticky residue that’s hard to clean off your device. 

Many believe that showering with their watch on will clean it, but water alone doesn’t remove the oily, sticky residue that bacteria cling to. In fact, moisture left behind after a shower can help bacteria thrive. 

How to keep your smartwatch (and your skin) safe this summer: 

So, what can you do to protect yourself? Start by making it a habit to clean your smartwatch at least once a week – more often if you’re exercising daily or spending time outdoors. 

Use a gentle soap or a disinfectant wipe recommended by your device manufacturer, and pay special attention to the band and any crevices. 

Make sure your watch is completely dry before putting it back on your wrist, especially before bed. 

And don’t forget about your bedding. If you wear your smartwatch to sleep, wash your pillowcases and sheets at least twice a week during the summer months to prevent bacteria build-up.