With the colder and darker months rolling in, many people will be spending more time in bed.
In one survey by the American Academy of Sleep Medicine (AASM), one in three US adults reports sleeping more in winter.
And a separate sleep study found participants tested in the winter slept an hour longer than those tested in the summer.
But with more time spent in bed, a leading health expert is warning about the dangers that could be lurking between the sheets and in your bedroom.
Dr Menachem Jacobs, an internal medicine resident at Yale New Haven Hospital in Connecticut, told the Daily Mail that poor air quality, hidden mold and even your mattress could all be quietly affecting your immune system without you realizing.
And these bedroom dangers could even fuel this season’s wave of winter illnesses like the common cold and flu.
Below, the Daily Mail reveals Dr Jacobs’ most frequently observed issues when it comes to bedroom hygiene and experts explain the best ways to resolve them.
With the colder months upon us, many of us will be spending more time in bed. Experts have revealed, however, how your bed could be making you sick (stock image)
A mattress filled with half a million dust mites
Dr Jacobs explained that as soon as the heat turns on, the warm, humid air ‘creates perfect conditions for dust mites to thrive.’
This can mean that by the time autumn arrives, a full-sized mattress can contain more than half a million of them.
He added: ‘These microscopic creatures feed on the skin cells we shed at night and leave behind droppings that are a leading trigger for indoor allergies.
‘For people with asthma or eczema, symptoms can feel like a seasonal flare-up, but it’s often the mattress fueling the problem.’
Symptoms of a dust mite allergy can include sneezing, a runny or stuffy nose, itchy eyes, coughing, wheezing, chest tightness and skin rashes.
To avoid a dust mite infestation Martin Seeley, the CEO at UK-based company MattressNextDay, told the Daily Mail he aways recommends using a zipped, hypoallergenic mattress protector, and washing your bedding weekly at 140F so ‘allergens do not get a chance to build up.’
Cold walls making you sick in your sleep
Dr Jacobs noted that beds are often placed against the wall to save space in apartments and houses, but in the colder months, those walls can become frigid, especially in older or poorly insulated homes.
He said: ‘Sleeping close to a cold surface can make it harder for your body to maintain its temperature and may leave you feeling achy or run down.
‘While it might not directly weaken your immune system, discomfort and poor sleep quality can still take a toll on your overall well-being.’
Bed expert Seeley recommended pulling the bed out from the wall, as even a slight gap ‘can make a big difference.’
This will help stop the colder air from hitting your body and let the mattress breathe properly, he explained.
Sweating in your sleep
While it might feel cooler, Dr Jacobs revealed that we still sweat in bed during winter and we can lose around 16 ounces of moisture through sweat and breathing in the night.
He explained that when the windows are closed, much of this moisture is absorbed by the mattress.
This in turn ‘creates a damp environment where bacteria and fungi can thrive.’
‘Over time, this can lead to musty odors and even trigger skin irritation or congestion,’ Dr Jacobs added.
To avoid this, Seeley highlighted the importance of stripping your bed on a weekly basis and giving it time to air out each morning before making it.
He said: ‘Crack a window for a bit, too. You will notice the whole room smells fresher and feels lighter.’
Dr Jacobs explained that as soon as the heating goes on, the warm, humid air ‘creates perfect conditions for dust mites to thrive’ (stock image)
Radiators drying you, and your bedding, out
With the indoor heating cranked up during the cooler months, Dr Jacobs said the air has a tendency to be drier.
He said: ‘It pulls moisture from your skin and throat, leading to cracked lips, dry eyes and irritation in the airways.
‘For people with asthma or respiratory sensitivities, that dryness can make it harder to breathe and get quality sleep.’
A solution to this could be using a whole-house or portable humidifier to add moisture to the air.
Meanwhile, drinking 15 cups for men and 11 for women of water and using moisturizers can keep the skin hydrated.
Seeley noted that dry air can also ruin your mattress.
He said: ‘Many people keep their beds next to the radiator without thinking about it.
‘That steady dry heat can really wear out a mattress over time as the foams dry out, the fabric gets brittle, and the whole thing starts to feel less supportive.
‘Try to leave around 20 to 30 centimeters [eight to 12 inches] between your bed and the radiator. It is just enough space to protect the mattress from heat damage and keep the room feeling more comfortable.’
Hidden mold
Sleep expert Dr Jacobs warned that autumn’s damp air and cold walls create ideal conditions for mold growth (stock image)
As nights grow cooler and damper, your bedroom could be harboring an invisible health hazard: mold.
Dr Jacobs warned that winter’s damp air and cold walls create ideal conditions for mold growth, especially if your bed is pushed up against the wall.
Moisture from condensation can become trapped behind the mattress, forming a hidden pocket where mold thrives.
‘The worrying part is that you might never see it,’ he said, noting that microscopic spores can spread through the mattress fabric.
These spores can aggravate allergies, trigger coughing, and even mimic cold symptoms.
‘Many people spend months treating what they assume are recurring colds, without realizing the real cause is a moldy bed,’ he added.
According to Seeley, a few simple habits can help stop mold from taking hold. He advised rotating your mattress monthly to keep it well-aired, wiping condensation from walls each morning, and opening curtains to let sunlight in.
‘Mold loves dark, damp corners,’ he said, ‘so regular light and airflow are your best defense.’
Germs lingering in winter bedding
Dr Jacobs told the Daily Mail: ‘With flu season starting in autumn, your bed becomes a hotspot for germs.
‘Viruses and bacteria can survive in warm bedding for days, which means if one person in the household is ill, the infection can easily spread back and forth through shared sheets and duvets.
‘Many people assume washing every couple of weeks is enough, but that allows germs to linger. Without realizing it, your bed can end up keeping the illness going.’
The Cleveland Clinic recommends swapping out your sheets for clean ones every one to two weeks or more often if you are ill, have allergies or own a pet.
And bedding should also be washed on a high temperature to make sure it is sufficiently cleaned.
Seeley said if someone in your home becomes unwell, you should ‘go beyond just washing the sheets.’
He advised: ‘Freshen the whole bed by airing the duvet, spritzing the mattress with a fabric-safe disinfectant spray, and changing pillowcases more often than usual. It is a simple way to stop germs spreading and keep your bed feeling fresh between washes.’
Dr Menachem Jacobs is a resident physician at Yale New Haven Hospital in Connecticut
Piling on layers and overheating your body
During winter, you may be tempted to pile on thicker duvets and turn up the heating to stay comfortable at night. But according to the sleep experts, this common habit could actually be disrupting your body’s ability to recover and fend off illness.
Dr Jacobs explained that deep, restorative sleep depends on a natural drop in core body temperature during the night.
When you sleep in an environment that’s too warm (from heavy bedding, blankets, or central heating) that cooling process is interrupted.
As a result, the body struggles to reach the deepest stages of sleep, which are crucial for immune repair.
‘If your temperature doesn’t fall properly, you’ll wake up tired and more vulnerable to infections,’ he said.
Seeley agreed, noting that feeling overheated or restless during the night is a clear warning sign that your bedroom might be too warm.
He advised swapping heavy duvets for breathable cotton sheets or lightweight layers, and, if possible, investing in a mattress or topper designed to regulate temperature. Keeping the bedroom around 65F, he added, ‘is the sweet spot for staying comfortable without overheating.’
