Washing bedding to kill fleas works, and it works on every life stage: a hot wash followed by a full high-heat dryer cycle will finish off adult fleas, eggs, larvae and cocooned pupae in anything that fits through the machine. Detergent and 20+ minutes of submersion drown adults on their own, and the dryer is the part that dries out and cooks whatever the water missed. What laundry cannot do is clear the rest of the house, which is where most of the population actually lives.
So treat washing bedding to kill fleas as step one of a three-to-four-week plan: launder, vacuum, treat the pet. Below are the actual temperatures, cycle times, fabric limits and bedding sizes you need, plus an honest note about where the published evidence runs out.
What Temperature Kills Fleas in the Washing Machine?
Any genuinely hot household wash does the job when you’re washing bedding to kill fleas. On a US machine, a “hot” fill usually lands around 130°F (54°C) or above, while “warm” is closer to 90–110°F (32–43°C) and “cold” sits at 60–80°F (16–27°C). A sanitize cycle, where your washer has one, uses an internal heater to push past 140–150°F (60–66°C).
Here is the honest part. University extension and pesticide-information sources consistently recommend hot water plus a hot dryer for pet bedding, but they don’t publish a precise kill temperature or exposure time for flea eggs in a washing machine. The National Pesticide Information Center’s flea guidance simply lists washing fabrics and bedding in hot water as part of an integrated approach alongside vacuuming and insect growth regulators. Anyone quoting you an exact “fleas die at X degrees for Y minutes in a washer” number is going beyond what’s actually been published.
The practical upshot: you do not need to hit a magic number, because a hot wash with detergent plus a full high-heat dry stacks three lethal conditions (submersion, surfactant, heat) on a fragile insect. Cold water with detergent still drowns adult fleas, which is exactly why flea-combing into a bowl of soapy water works. Cold is just far less reliable on eggs and cocoons, so use it only when the care label forces your hand, and lean harder on the dryer.
Wash Settings, Translated
| Setting |
Typical water temperature |
Use it for |
Flea notes |
| Sanitize |
140–150°F+ (60–66°C+) |
White cotton sheets, towels, sturdy pet bedding covers |
Most reliable option; hardest on fabric and color |
| Hot |
About 130°F (54°C) |
Cotton sheets, pillowcases, cotton duvet covers |
The standard recommendation in extension guidance |
| Warm |
90–110°F (32–43°C) |
Colors, blends, down-filled items |
Acceptable if you follow with 30+ minutes on high heat |
| Cold |
60–80°F (16–27°C) |
Silk, wool, anything marked cold-only |
Drowns adults; unreliable on eggs unless you dry hot |
Your “Hot” May Not Be Hot
Two things quietly sabotage a hot wash. First, most water heaters are set to 120°F (49°C) to prevent scalding, and your washer can’t deliver water hotter than what arrives at the inlet unless it has its own heater. Second, plenty of modern machines blend cold into the hot fill to hit a target temperature, so “hot” on the dial can arrive lukewarm.
Check it in five minutes. Start a hot cycle with an empty drum, let it fill for a minute or two, pause the cycle, and drop an instant-read or candy thermometer into the water. If you’re seeing under 110°F (43°C), your dryer is now the main event, not the wash.
Washing Bedding to Kill Fleas, Step by Step
- Bag it where it lies. Bring a trash bag to the bed or the pet bed, and stuff items straight in. Don’t shake or fling anything — flea eggs are smooth, non-sticky and roll off fabric, so a good shake seeds your hallway carpet.
- Carry it sealed. Knot the bag, carry it to the machine, and empty it directly into the drum.
- Load loose. Fleas and eggs hide in folds and seams. Fill the drum no more than about three-quarters full when items are loose; you should be able to push a flat hand down past the load to the bottom of the drum.
- Run the hottest cycle the label allows, with your normal detergent and a long wash time. Skip fabric softener — it does nothing here.
- Dry on high for at least 30 minutes, and once the load is dry, give it another 10–15 minutes. Comforters and thick pet beds hold damp cores long after the outside feels dry, and the core is where a surviving cocoon would be.
- Deal with the bag. Tie it shut and put it straight in an outdoor bin, or wash it if it’s reusable. Wipe out the hamper too.
- Vacuum the bare bed while the bedding is out. Mattress seams, the box spring, the frame slats, the headboard join and the floor under the bed.
- Repeat weekly for three to four weeks. Michigan State’s flea guidance recommends washing pet bedding in hot water and drying hot at least once a week during an active problem.
While the mattress is stripped is also the right moment to deal with anything you’ve been ignoring on the surface — our guide to cleaning mattress stains covers the safe methods for each stain type.
Which Bedding Can Take a Hot Wash (and What Size It Is)
Before you commit a duvet to 140°F, know two numbers: what the item measures, and whether your drum can move it. A comforter that can’t tumble freely doesn’t get clean, doesn’t rinse and doesn’t dry to the core.
| Item |
Typical size |
Hot wash? |
Dryer |
| Flat sheet, twin |
66 x 96 in (168 x 244 cm) |
Yes, cotton handles hot |
High heat, 30+ min |
| Flat sheet, queen |
90 x 102 in (229 x 259 cm) |
Yes |
High heat, 30+ min |
| Flat sheet, king |
108 x 102 in (274 x 259 cm) |
Yes |
High heat, 40+ min |
| Comforter, full/queen |
90 x 90 in (229 x 229 cm) |
Warm to hot if the label allows |
Long, low-to-medium for down; add dryer balls |
| Comforter, king |
104 x 88 in (264 x 224 cm) |
Often too big for a home drum |
Laundromat large-capacity machine |
| Down or feather duvet |
As above |
Warm, gentle, mild detergent |
Low heat, hours, fully dry or it mildews |
| Wool blanket or topper |
Varies |
No — hot water felts and shrinks it |
Air only; consider professional cleaning |
| Memory foam pillow or topper |
Varies |
Never machine wash the foam core |
Wash the removable cover hot; vacuum and air the foam |
| Pet bed, removable cover |
Varies |
Yes, hot |
High heat, 30+ min |
| Pet bed, sewn-shut foam base |
Varies |
Check label; many are hand-wash only |
If it won’t wash hot, replacing it is often the cheaper fix |
Sizes vary by brand, so measure your own before you buy a replacement. Washing bedding to kill fleas is only worth doing if the fabric survives it. If you’re worried about a hot cycle wrecking sheets you like, our breakdown of what temperature to wash sheets without shrinking explains which fibers tolerate what, and this guide to bedding materials covers how each fiber behaves in the wash.
The Drum-Capacity Question
Home washers sold in the US commonly run 4.0–5.0 cubic feet (113–142 liters) of drum volume; your manual lists the exact figure. A queen comforter is usually manageable in that range. A king comforter, a thick mattress topper or two pet beds at once usually are not, and jamming them in defeats the purpose. Laundromat machines in the 40–80 lb (18–36 kg) class handle those easily, and their hot water is typically hotter than home supply. Bag the items for transport, and don’t load the clean laundry back into the same bag.
What Laundry Won’t Fix: The Cocoon Problem
The reason fleas “come back” a week after you’ve cleaned everything isn’t failure on your part. It’s the cocoon.
Fleas run a four-stage life cycle — egg, larva, pupa, adult. Eggs laid on your pet fall off wherever the animal goes and hatch in roughly three to six days into larvae, which feed on organic debris deep in carpet and crevices. The larvae then spin cocoons, and that pupal stage is the problem: the cocoon shields the developing flea from insecticides, and adults keep emerging for weeks. UC Statewide IPM Program guidance notes that treating carpet kills larvae but not pupae, so fleas may continue emerging for up to two weeks afterwards, and recommends vacuuming regularly through that window rather than reapplying pesticide. Pest-management literature puts the emergence tail at two to four weeks, occasionally longer.
The Three Things That Actually End It
- Treat every pet in the house, with a product your vet recommends, on schedule. One untreated cat re-seeds the whole house. UC IPM rates shampoos, powders, dusts and dips as less effective and more hazardous than modern on-animal products.
- Vacuum daily, then bin the bag. Extension guidance from Texas A&M is blunt about this: vacuum under furniture, cushions, chairs, beds and along walls, and discard vacuum bags at least weekly, because fleas can continue developing inside the bag. Vacuuming also triggers cocooned adults to emerge, which is what you want — out in the open, where treatments reach them.
- Use an insect growth regulator on the carpet if the infestation is more than light. Look for methoprene or pyriproxyfen on the label; these stop eggs and larvae from developing rather than killing adults. Iowa State’s guidance is that light infestations may clear with thorough vacuuming alone, while moderate to heavy ones usually need a residual product.
How to Tell Fleas Are in Your Bed, Not Just on Your Pet
Washing bedding to kill fleas is wasted effort if you’re chasing the wrong insect. Adult fleas are 3–4 mm long (about 1/8 inch), flattened side to side, and reddish-brown to nearly black. They’re fast and they jump, so you’ll often see the evidence before the insect.
The Flea Dirt Test
Look for gritty black specks on white sheets, in mattress seams, or in the fur along your pet’s spine and tail base. Brush some onto a damp white paper towel. If it smears rust-red, that’s digested blood — flea dirt, not household grime. This is the single most reliable at-home confirmation.
The White Sock Test
Consumer Reports’ pest coverage passes along an old IPM monitoring trick: put on white socks and walk slowly around the suspect rooms. Fleas hop on, and against white they’re easy to spot.
Bites on You
Cat fleas — the species you’ll almost certainly be dealing with indoors — live on dogs and cats and will bite humans, but they don’t set up residence on people. Bites tend to cluster on ankles and lower legs. If bites are on your torso in a line, consider bed bugs instead; the treatment is completely different, so identify before you act.
Check These Five Things Before Your First Flea Wash
- Water heater setting. This number decides whether washing bedding to kill fleas leans on the washer or the dryer. If it’s at 120°F (49°C), plan on relying on the dryer or a sanitize cycle.
- Care labels on everything. Wool, silk, latex and foam are the ones that will punish a hot cycle. Sort before, not mid-load.
- Drum capacity versus item size. Measure the comforter; if it can’t tumble with room to spare, take it out.
- Dryer vent airflow. A clogged vent means long cycles that never reach temperature. Clear the lint trap every load during a flea campaign — you’re running a lot of them.
- Whether you have a mattress protector. A zippered, washable protector means next time you strip a wash-safe barrier instead of scrubbing the mattress itself. If you’re rebuilding the bed anyway, our complete guide to bedding layers is a sensible place to plan what goes back on.
Mistakes That Keep Fleas Coming Back
- Washing bedding to kill fleas once and stopping. One wash removes the current wave. The cocoons hatch over the following two to four weeks.
- Treating the house but not the pet, or treating one pet of three.
- Overstuffing the washer so nothing actually agitates.
- Pulling a comforter out of the dryer while the core is damp. That’s the one spot heat didn’t reach.
- Re-using the transport bag for clean laundry.
- Reapplying insecticide every time you see a new flea. UC IPM specifically advises against re-treating during the two-week emergence window; vacuum instead.
- Leaving the vacuum bag in the machine for a week while larvae mature inside it.
Washing Bedding to Kill Fleas: FAQ
Does washing bedding kill flea eggs?
Yes — that’s the main reason washing bedding to kill fleas is worth the effort. Eggs are the least durable stage, and a hot wash with detergent plus a high-heat tumble dry deals with them. If you can only wash cool, the dryer carries the load — run it hot for 30 minutes minimum after the item is dry to the touch.
Can fleas survive a cold wash?
Adults rarely survive a long cold wash with detergent, because they drown. Eggs and cocooned pupae are tougher, and cold water alone is not something you should rely on. Cold wash plus hot dryer is a reasonable compromise for delicate items; cold wash plus air dry is not.
How often should I wash bedding during a flea infestation?
Weekly for pet bedding and human sheets while the problem is active, which typically means three to four weeks. Once you’ve gone two weeks without seeing a flea, drop back to normal. Consumer Reports’ prevention advice for households with pets is hot-washing animal bedding every two to three weeks as routine maintenance.
Do fleas live inside mattresses?
Not usually inside the mattress the way bed bugs do. Fleas and their eggs collect in seams, tufting, the gap between mattress and frame, and the carpet underneath. Vacuuming seams thoroughly and washing the bedding hot handles the bed itself; the floor under and around it needs more attention than the mattress does.
Do vinegar, salt or baking soda on bedding kill fleas?
The evidence here is thin, and I’d rather say so than sell it. Vinegar isn’t an insecticide and won’t kill eggs; salt and baking soda are sometimes suggested to dry out larvae in carpet, but you won’t find them in university extension control recommendations, and both are abrasive to carpet fibers and hard on a vacuum. Spend the effort on the hot wash, the vacuum and the pet instead.
How long until the fleas are actually gone?
Plan on three to four weeks of washing bedding to kill fleas, daily vacuuming and on-pet treatment before the house goes quiet. Seeing fleas in week two doesn’t mean the plan failed — it means cocoons are hatching on schedule. If you’re still finding them after six weeks with everything treated, that’s the point to call a licensed pest-control operator.
About the Author
Joseph Rett is the founder of Cozy Bed Quarters, a Phoenix-based sleep and bedding resource. He researches sleep science and bedding products and writes about building comfortable, low-maintenance sleep spaces. This article is general guidance, not veterinary or pest-control advice — for treatment decisions about your animals, talk to your vet.
Updated September 2026.
