Your bedsheets are likely dirtier than you think — here's how to wash sheets to get them clean and bright

• Bedsheets accumulate skin cells, body oils, sweat, dust mites, and more.
• You should wash your sheets weekly to keep them clean.

We spend a significant amount of time in bed, and sheets can be a pricey purchase. It's important to care for them properly so they last.

While most bedsheets are cotton and can withstand high temperatures, others, like linen sheets, have different care instructions. Even if you're sure your sheets are cotton, you'll want to read the label before washing them. They may have coatings or other properties that don't work well with high heat, bleach, or ironing.

Here are some tips for washing your bedsheets.

How often should you wash your sheets?

All the experts we spoke with said you should wash your sheets once a week for a variety of reasons.

"Even if you are a very clean person and shower every day, after a few days your sheets become soiled with dead skin cells, sweat, body oils, and other gross stuff," said Jessica Samson, cleaning expert with The Maids.

Dust mites, microscopic spider-like pests, live on dead skin cells often found on bedding. "If you are sensitized to dust mites, and you have nasal allergies or asthma or eczema, you do benefit from dust-mite-avoidance measures," said Dr. Maya Jerath, an allergist-immunologist with the Barnes-Jewish West County Hospital. That includes regularly washing sheets, comforters, and stuffed animals and encasing mattresses and pillows in protective covers.

"If someone is sick in bed or prone to accidents (potty training children or pets, for example), you'll want to wash your sheets more frequently, and as soon as possible after any accidents," said Corinna and Theresa Williams, co-founders of the eco-friendly laundromat Celsious, in an email.

How to wash sheets without bleach

Both Samson and the Williams sisters said there are ways to fully clean sheets without bleach. "First, you want to treat all stains before washing the sheets," said Samson.

She said most cotton sheets don't require special care and can be washed in hot water, but you should still read the labels.

"We're big proponents of not using chlorine bleach," said the Williams sisters. "It's harsh on fabric, which isn't good for longevity and can contribute to yellowing over time." Instead, they recommend an oxygen booster to treat stains and keep whites bright.

Bleach is harsh on sheets. Pretreating stains and using an oxygen booster can help keep them clean and bright.

How to wash cotton sheets

Wash: Hottest setting sheets can withstand

Dry: Low heat

Avoid: Fabric softener

"Your everyday sheets should not have complicated care instructions, and the material should be able to withstand warm or hot washes for hygienic reasons," said the Williams sisters.

They suggest looking at care instructions before buying sheets, then washing them on the warmest setting they can withstand.

The Williamses also recommend drying cotton sheets on low heat for longevity. You should also avoid fabric softener, which coats fibers and can affect sheets' absorbency.

How to wash linen sheets

Wash: Lukewarm or cold

Dry: Low

Avoid: Fabric softener

"Linen sheets are prone to shrinking in the wash if you use the hottest setting," said Samson. She and the Williamses said to use lukewarm or cold water.

To keep linen soft, the Williams sisters add a ¼ cup of white vinegar to the washer's fabric softener compartment and use dryer balls in the dryer. You should also dry linen sheets on low, they said.

If you don't like linen's natural wrinkles, you can use a steamer or warm iron, the Williams sisters said, as long as the label doesn't caution against it.

How to wash sheets in cold water

Washing bed sheets in hot water is important if you have dust-mite sensitivity. Dr. Jerath said to wash sheets once a week in water hotter than 130 degrees Fahrenheit.

"Always use the hottest water that your sheets can handle, and always read the label before cleaning your sheets," said Samson.

However, Corinna and Theresa Williams acknowledge that many people prefer to wash laundry in cold water to save energy. "If you like, add ¼ cup of white vinegar to the rinse cycle to help flush out odor," they said, and run a warm or hot cycle monthly. Washing clothes at 140 degrees Fahrenheit will help kill viruses and bacteria.

Water needs to be 130 degrees Fahrenheit to kill dust mites and 140 degrees to kill viruses and bacteria.

Insider's takeaway

Washing sheets is a balance between making sure they're actually clean and ensuring they last as long as possible. To get your bedsheets really clean, it's best to use hot water, over 130 degrees Fahrenheit to get rid of dust mites and over 140 degrees to help kill viruses and bacteria.

However, some bedsheets don't withstand high temperatures well. You'll want to read the label for specific care instructions. Using bleach and fabric softener will negatively impact your sheets, as can drying them on high heat.