Quick answer

How long to leave an electric blanket on UK: none of the UK safety bodies we checked gives a number of hours. Pre-heat it for the time your manual gives. Leave it on overnight only if its controller or manual says that model is for all-night use, turn it down to that setting before you get in, and switch it off when you get up; if it does not say so, or you cannot find out, switch it off and unplug it before bed. With diabetes, switch it off before getting into bed whatever the manual says. Do not use one at all with emollient creams (the moisturisers used for dry skin or eczema), continence issues, an air-flow or pressure-relief mattress or a baby in the bed, or for a child under three or anyone who cannot feel or react to overheating.

Table of contents

What the controller is telling you

The UK safety bodies we checked answer this with a condition rather than a number. Devon and Somerset FRS puts the test in one line: "Don't switch it on overnight unless it has a thermostatic control and is designed to be left on." Greater Manchester, London and Hereford and Worcester fire services say much the same. Electrical Safety First's press release is looser: "either switch it off before bed or make sure it has an automatic shut off". This guide follows the fire services, and that sends you back to your own blanket.

Four things to check

Take them in this order. Only the first two can tell you a blanket is designed to stay on overnight; a thermostat, a timer or overheat protection describes the design but never gives permission. No manual? Find the model number on the rating label and look the manual up on the maker's website. If neither the controller nor the manual says it can stay on all night, treat it as a pre-heat blanket: off and unplugged before you get in. And if you are in one of the groups further down this page, the stricter of their rule and these checks applies.

  • The controller's own labels. Look for the words "all night" printed as a setting, not as marketing on the box. Dreamland uses it as a setting name and tells owners to "switch your control on to all night setting before retiring for bed".
  • The manual's overnight sentence. Silentnight's underblanket manual names a number: "If using the blanket all night or for an extended period, please use low heat setting 1." Slumberdown's: "If you are planning to use the blanket all night long, keep it on low heat: 1."
  • A timer, and how long it runs. Silentnight's heated throw cuts out after two hours and its manual says not to fall asleep with it on; a longer cut-off is not permission either.
  • Overheat protection. Worth having, but it settles nothing: Silentnight prints the same overheat protection logo on a throw you must not fall asleep under and on an underblanket you may.

The turn-down instruction

Being rated for all-night use is one part of the question, the setting is another, and who is in the bed is the third. Morphy Richards' 2006 underblanket manual spells out the sequence: pre-heat at level 2 or 3 for roughly 60 to 90 minutes, then "Move the heat setting on the control switch to heat level 1. This setting will provide safe and comfortable heat to sleep on all night." That sequence is for a blanket rated for all-night use; on a pre-heat blanket, level 1 is still off and unplugged before you get in.

Silentnight's underblanket and heated throw manuals both warn: "Constant use at the highest temperature may cause skin irritations or burns so must be avoided."

Underblanket, overblanket, throw: not the deciding factor

The tempting rule is that underblankets can stay on and throws cannot. Manuals do not sort that neatly: Silentnight's heated throw manual says "Do not fall asleep with this device on.", while Lakeland's tells you to turn its throw, which switches itself off after three hours at most, to level 1 "before falling asleep". Neither gives permission for a night in bed: unless your throw's controller or manual says it is for all-night use, it is off and unplugged before you get in. If your throw's manual says not to fall asleep with it on, dozing off on the sofa counts too. Hereford and Worcester FRS: "Never use an electric underblanket as an electric overblanket, and vice versa".

Month by month through the year

The work that makes November safe happens in October.

October

Electrical Safety First: "Before plugging it in, check the blanket and its cable for damage, especially if it's been in storage over the summer." Check the mains cable for rodent damage too: its advice page says "Signs of rodent damage, frayed wires, or scorch marks means it needs replacing immediately." And test your smoke alarm: Electrical Safety First says to "Test alarms at least once a month" and to have "at least one smoke or heat alarm per floor in your property".

November

November becomes a sequence: on for the pre-heat time, then down, or off and unplugged, before you get in, and off when you get up.

On cold nights, Dorset and Wiltshire FRS says "Never use a hot water bottle in the same bed as an electric blanket, even if the blanket is switched off."

December and January

Cold-snap months, when the temptation is to leave it high and leave it on. A cold night does not change the rule: once you are in bed it stays on its all-night setting or it is off, and it does not go back up if you wake cold.

February and March

By February, run the inspection again: a blanket slept on nightly since October has had four months of use, washing and spills. If it was washed as its label allows, Devon and Somerset FRS: "Make sure the blanket is fully dry after it's been washed before you turn it on again." If it got wet any other way, see "If something goes wrong" below.

April to September

Leave it flat on the bed, unplugged, or roll it, and do not fold it. Devon and Somerset FRS: "Store your blanket flat; never fold or crease the blanket. It should not be used if it has been creased or folded." Greater Manchester FRS says "Store electric blankets flat or rolled.", while Electrical Safety First says it "can be left on the bed all year round (unplugged) or loosely folded and stored in a cool dry place", so folding is where they split. Let it cool before it is stored away, as Silentnight's underblanket manual says, and once it is stored, Electrical Safety First says "Moth-proofing chemicals should not be used on it, or heavy items placed on top of it."

From the airing cupboard to the next morning

  1. Inspect it before it goes near a socket. Greater Manchester and Hereford and Worcester fire services give the same nine-point list: fraying fabric, scorch marks, exposed elements, creasing or folding, soiling, damp patches, damaged or missing tie tapes, worn flex, loose connections. Add Devon and Somerset's wire test, "If the wires are no longer in straight lines, the blanket shouldn't be used", and check the mains cable for rodent damage. If you are in any doubt about its condition, Greater Manchester FRS says contact the manufacturer before using it, and Hereford and Worcester FRS says "bin it and buy a new one".
  2. Check its age. Electrical Safety First: "It is recommended to replace your electric blanket every ten years." If you cannot tell how old it is, we would treat it as over ten.
  3. Fit it flat and hold it there. An underblanket goes on the mattress, spread out fully, secured with its tie tapes or elasticated straps; Hereford and Worcester FRS says tying them to the bed or mattress "stops them slipping and creasing". Plug into the closest socket at the pillow end so the lead is not stretched; Silentnight's underblanket manual allows "an extension lead if needed to ensure that the product lead is not stretched", so check what yours says. Dreamland's H5611 underblanket instructions say to "Avoid placing the control switch below the pillow or between the sheets or blankets when the appliance is connected." Silentnight's manual says the blanket "must not be used on a sofa bed or inflatable air bed". Electrical Safety First recommends against underblankets on adjustable beds; if your manual allows one, between them the Silentnight and Dreamland H5611 manuals say to check that the blanket and cord cannot become trapped, rucked or stretched.
  4. Cover it, then pre-heat. Silentnight: it "will start to heat after a few minutes, providing it is covered correctly with a duvet or blanket". Pre-heat for the time and at the setting your manual gives: Dreamland says its Intelliheat blankets "heat up in 5 minutes", while Morphy Richards' 2006 manual says to allow "approximately 60-90 minutes" at level 2 or 3. Stay in the house while it warms: every warning sign below needs somebody there to notice it. If the controller buzzes, crackles or smells while it warms, unplug it; if anything smokes, get out and call 999. See "If something goes wrong" below.
  5. Turn it down or off before you get in. If your blanket is all-night rated, drop it to its all-night setting, or to setting 1 where the manual names a number; if it names none, we would use the lowest. If it is not all-night rated, switch it off at the controller and pull the plug out of the wall, and Dreamland's H5611 instructions warn: "DO NOT pull the power cord or the appliance to remove the plug from the socket." If you are in one of the groups under "Who should switch it off, or not use one at all" below, the stricter rule applies.
  6. Then leave it alone. Greater Manchester FRS: "Never use a hot water bottle or have drinks while using an electric blanket. Spills can cause electrical faults and increase the risk of fire." Keep pets off it too: Lakeland's and Slumberdown's throw booklets say "DO NOT use this appliance to warm animals.", and Blue Cross tells cat owners to "avoid electric blankets, as they can burn your cat", adding that the cord "can be dangerous if chewed". If you wake up cold, it stays on its all-night setting or it stays off; it does not go back up; add a layer of bedding instead.
  7. Check your manual before using a plug-in timer or smart plug. Silentnight's heated throw manual says "This appliance is not intended to be operated by an external timer or separate remote-control system", and Lakeland's throw booklet says "Not recommended to be used with a plug in timer switch". And no timer, the blanket's own included, is permission to fall asleep with a blanket that is not designed for all-night use: that one is off and unplugged before you get in.
  8. If you have the Silentnight Smart Wi-Fi Plug (model A6), sold from 2017 to 2022 on its own and bundled with Silentnight electric blankets, stop using it. It has been recalled for a serious risk of electric shock, and the Office for Product Safety and Standards notice says: "We recommend that you stop using this product immediately and contact recall@silentnight-bedding.co.uk / 0330 107 1052 for next steps."
  9. Switch it off in the morning. Morphy Richards' manual: "Always ensure that the heat setting is moved to the OFF position when you get up the next day, or after airing the bed."

If something goes wrong

  • Anything is smoking or on fire. Get out and call 999, and do not try to put it out. London Fire Brigade: "Don't take any risks - get out, stay out, shut the doors behind you and call 999." and "Don't try to fight the fire - you could put yourself and others in danger." If anyone in your home would struggle to get out quickly, it says to "make extra plans to get them to safety, and book a free home fire safety visit for extra expert advice."
  • One part gets much hotter than the rest, or it smells scorched. Get out of bed, switch it off and unplug it, and do not use it again until it has been checked or replaced. Greater Manchester FRS warns that uneven heating "may lead to overheating and a fire starting", and says of signs of damage such as scorch marks: "If it appears damaged, stop using it immediately."
  • It gets wet while it is on, or comes out of storage damp. If you are in bed, get out, then with dry hands switch it off and unplug it: Essex County FRS says "Do not touch the blanket if you have wet hands or feet, and never use the blanket if it is wet or damp". Hereford and Worcester FRS: "if your blanket does get wet, don't use it. Never switch it on to dry it." Damp patches are on its list of danger signs, and for those it says to "have it checked or replaced".
  • The controller, plug or socket buzzes, crackles, smells, shows burn marks or feels hot. Unplug it and stop using it. On plugs and sockets, Electrical Safety First says: "Don't ignore burn marks, 'arcing' (buzzing or crackling) sounds, fuses blowing, circuit-breakers tripping, or if it feels hot to touch." and "Unplug and contact the retailer, manufacturer, or a qualified repair technician." Its list of reasons to replace a blanket includes a control "making a buzzing sound when switched on and/or is giving off a smell" and a connector that is "damaged or over-heating".
  • It has left a burn or blister on your skin. Switch the blanket off and unplug it. The NHS says: "Hold the burn or scald under cool running water for 20 minutes. Do this as soon as possible, within 3 hours of it happening." Then "Remove any clothing or jewellery that's near the affected area - but do not remove anything that is stuck to the affected area." Call 999 or go to A&E if the burn "is very large or deep", "is on your face, genitals or bottom" or "has been caused by an acid or chemical, or by electricity", and "Do not drive to A&E. Ask someone to drive you or call 999 and ask for an ambulance." If you are not sure what to do, the NHS says to get help from NHS 111, and it says "do not put any creams, oils or butter on burns or scalds" and "do not burst any blisters". With diabetes, read the foot advice under "Diabetes" below as well.
  • It might be on a recall list. For Dunelm's Cosy & Warm electric blankets from the 2022 and 2023 batches, the Office for Product Safety and Standards notice says to "stop using it immediately and contact Dunelm on 0333 234 0870 to claim a free replacement cable", or to return the blanket and cable to Dunelm for a full refund. B&Q recalled its GoodHome Saturnia electric blanket: "Consumers are advised to stop using the product immediately, unplug it from the mains and return it to their nearest B&Q store for a full refund." Recalls also cover a Snuggla king-size underblanket sold via Amazon, eBay, Etsy and TikTok. Register your blanket, and check the current list on GOV.UK's Product Safety Alerts, Reports and Recalls page: if yours is on it, stop using it and do what the notice says. The Silentnight Smart Wi-Fi Plug recall is in the procedure above.
  • It was folded, or has a crease. Devon and Somerset FRS says a blanket "should not be used if it has been creased or folded", while Electrical Safety First allows loose folding for storage. If yours was loosely folded, lay it flat and run the rest of the inspection above before it goes near a socket: if it still shows creasing or folding, Hereford and Worcester FRS says to "have it checked or replaced", and if the wires are no longer in straight lines, Devon and Somerset FRS says "the blanket shouldn't be used".
  • It rucks up or slides down the mattress. Greater Manchester FRS says folding or bunching "can cause uneven heating, which may lead to overheating and a fire starting". Secure it with its tie tapes or straps; if they are missing or damaged, have it checked or replaced, and never pin it: Electrical Safety First says "don't insert or use pins to hold the blanket in place on the bed".
  • It is over ten years old. Replace it: Electrical Safety First and several UK fire services put replacement at ten years.

Who should switch it off, or not use one at all

With diabetes, switch it off before getting into bed whatever the manual says. Do not use one at all with emollient creams (the moisturisers used for dry skin or eczema), continence issues, an air-flow or pressure-relief mattress or a baby in the bed, or for a child under three or anyone who cannot feel or react to overheating.

Diabetes

Diabetes UK's cold weather guidance, last reviewed on 9 October 2025: "If you're using an electric blanket, always turn it off before getting into bed and make sure you have checked the manufacturer's recommendations before use. This is because if you've lost sensation in your feet you may not notice when they are getting too hot and starting to burn."

If you have diabetes, an all-night rating changes nothing: switch it off before you get in. The rule sits under Diabetes UK's "Check your feet" advice, and its neuropathy page warns about lost feeling "especially if you don't realise that this has happened". If you already know you have lost feeling in your feet, the rule under the next heading is stricter: do not use one. Its cold weather page also says to "Always remove the hot water bottle from your bed before getting in." Check your feet every day, and if you find a mark or blister, Diabetes UK says: "If you notice something new that you're worried about, like a cut or blister on your foot, call your GP or foot protection team straight away. If you can't get through, call 111 for advice." Its page on serious foot problems lists the signs that need urgent care. For a fresh burn, start with the first aid under "If something goes wrong" above.

Dementia, and anyone who cannot react to overheating

Silentnight's heated throw manual says the appliance "must not be used by people sensitive to overheating or other vulnerable people who are unable to react to overheating". Electrical Safety First says not to use one on the bed of "a person who may have a condition that makes them insensitive to heat". The Alzheimer's Society advises that where a blanket is used, it should have "safety features such as an automatic shut-off time and a sensor to prevent overheating". Put together: if the person in the bed could not notice overheating or react to it, do not use one on their bed. The Alzheimer's Society's advice is about the features to insist on where a blanket is used at all; a shut-off does not make a blanket safe to sleep with. If you are not sure they could manage the whole routine alone every night, we would not set one up for them.

Continence issues

Age UK: "It's important you don't use an electric blanket if you experience continence issues, as they can be dangerous if they get wet." Greater Manchester FRS puts it in a flat do-not-use list alongside pressure-relieving devices and emollient creams.

Air-flow and pressure-relief mattresses, and inflatable beds

Never. London Fire Brigade explains that a punctured airflow mattress lets escaping air spread a fire rapidly, and "the emergency back up battery may also continue to pump air, which can cause the fire to burn longer and with greater intensity". Its equipment page gives the rule in one line: "Never use an electric blanket on an airflow mattress." Manufacturers rule out inflatable beds too: Silentnight's manual says the blanket "must not be used on a sofa bed or inflatable air bed", and we would keep one off a blow-up guest bed whatever the brand.

Emollient creams

The NHS describes emollients as "moisturising treatments applied directly to the skin to soothe and hydrate it", which covers the everyday moisturisers, creams and ointments used for dry skin, eczema or psoriasis. The MHRA's Drug Safety Update warns that emollient residue builds up on "clothing, bedding, dressings, and other fabric" and makes it ignite more easily, and that the risk "cannot be excluded with paraffin-free emollients". The MHRA does not name electric blankets. It is London Fire Brigade, Greater Manchester FRS and Devon and Somerset FRS that turn it into a blanket rule: if you use emollient creams, do not use one. The residue the MHRA describes is in the bedding, so we would apply that rule if anyone who sleeps in the bed uses them.

Babies and young children

The NHS, on its sudden infant death syndrome page: "Babies should never sleep with a hot water bottle or electric blanket, next to a radiator, heater or fire, or in direct sunlight." Silentnight bars children under three entirely "due to their inability to react to overheating" and allows three to eight only "under supervision and with the control always set to the lowest temperature setting", and Electrical Safety First adds that a blanket used by a young child should have controls a parent or carer can pre-set, "who should be satisfied the child is able to use it safely". Where those overlap, take the strictest: nothing for a child under three, and if a baby or a child under three may end up in your bed at any point in the night, treat yours as pre-heat only, off and unplugged before you get in, because you will not reliably wake enough to switch it off when they arrive. For three to eight, we would switch it off before they fall asleep, and a child who wets the bed falls under the continence rule above.

Pacemakers

Not an outright ban, but you cannot keep 15cm from an underblanket you are lying on, so the distance decides it. The British Heart Foundation's answer is "Yes, but try to keep them 15cm (6ins) away from your pacemaker", and it adds "You can also ask your clinician or pacing clinic for advice." If you cannot keep that distance from the blanket while you sleep, switch it off and unplug it before you get in. Dreamland's H5611 underblanket instructions go further: "It is recommended that people with pacemakers do not use the heated bedding for all night use. It may be used to preheat the bed but the heated bedding must be switched off and un-plugged from the socket before going to bed."

Frequently asked questions

Can I sleep with an electric blanket on?

Only if your model is designed for it, and not for everyone even then. UK fire services put it as an exception: unplug before you get into bed unless the blanket has a thermostat control designed for safe all-night use, and if yours qualifies, turn it down to its all-night setting, or the setting its manual names, before you get in. Do not use one at all with emollient creams (the moisturisers used for dry skin or eczema), continence issues, an air-flow or pressure-relief mattress or a baby in the bed, or for a child under three or anyone who cannot feel or react to overheating, and with diabetes, always switch it off before getting into bed. Whoever uses it, switch it off when you get up.

Can I put my electric blanket on a smart plug or a timer?

Check your manual first, because some say no: Silentnight's heated throw manual says it "is not intended to be operated by an external timer or separate remote-control system", though not every manual carries that clause. No timer, the blanket's own included, is permission to fall asleep with a blanket that is not designed for all-night use. If you own the Silentnight Smart Wi-Fi Plug (model A6), stop using it: the Office for Product Safety and Standards notice says "We recommend that you stop using this product immediately and contact recall@silentnight-bedding.co.uk / 0330 107 1052 for next steps."

Can I wash an electric blanket?

Only if its label or manual says so, and many modern ones do. Silentnight's can be hand washed, or machine washed "as wool at 40°C", but not dry cleaned, while Russell Hobbs' RHEDB6002 says air dry only. Where your manual allows washing, detach the controller first and never immerse the controller, and never switch the blanket on until it is completely dry, then inspect it before you use it again.

My electric blanket is ten years old. Is it still safe?

Replace it. Electrical Safety First recommends replacing an electric blanket every ten years, and Nottinghamshire's testing events found age the biggest single factor behind failures. A test is for a younger blanket: Oxfordshire's free scheme failed over 36 per cent of the 920 blankets it tested in 2025.

Where can I get an electric blanket tested?

Check your own county, because this is a patchwork rather than a national service: Devon and Somerset FRS, for one, says "We are no longer running electric blanket testing at our stations." Oxfordshire County Council still runs free checks, which "must be booked in advance to be guaranteed". Age UK says the Chartered Trading Standards Institute "can help you find a trusted trader", and Dorset and Wiltshire FRS says to get it tested by a qualified electrician.

Is an electric blanket cheaper than heating the room?

It can be, although the figure depends on your tariff and your model. Electrical Safety First puts blankets at "typically 60-100 watts when in use depending on the model and settings" and says one "can be more cost-effective than heating an entire room or using a portable heater as an electric blanket delivers concentrated heat and can be used on lower settings and for short periods." Do not work out a nightly cost by multiplying watts by hours, because a thermostatic blanket cycles on and off once it is at temperature, so that sum is a ceiling and not a bill.