If you’ve ever tossed a load of laundry into the dryer only to forget about it until two days later, you’re not alone. While most of us intend to pull our clothes (or sheets or towels) out of the machine the moment the cycle ends, life can get in the way.

Leaving your clean clothes in the dryer can cause extra work for you, though. The longer you let them sit in a pile, the more likely it is that you’ll return to a drum full of wrinkled clothing. So, how long is too long to leave laundry in the dryer? To get the answer, we spoke with a laundry scientist who explains why fabrics wrinkle, how long you can realistically leave clothes in the dryer, and the smartest ways to rescue your laundry (without lugging out the ironing board!) once creases set in.

Sammy Wang is a fabric care laundry scientist with Procter & Gamble.

How Long Can You Leave Clothes in the Dryer?

While there’s no universal timeline, laundry scientist Sammy Wang explains that certain conditions affect how quickly wrinkles form. “There are a few factors that will impact how quickly clothes will wrinkle in the dryer, including temperature, fabric type, and load size,” she says. Temperature plays a significant role in how fast crisp folds turn into stubborn creases. “Since clothes will essentially begin to wrinkle in the dryer as soon as they cool down, try to remove them as soon as you can and fold or hang them, ideally within an hour," she says.

Your best bet is to unload the dryer within 60 minutes if you’re aiming to avoid wrinkles. Anything beyond that point means as fabrics cool, fibers settle, and creases begin to lock into place.

This isn't a hard and fast rule, though, because some fabrics wrinkle more quickly than others. “Typically, cotton or other natural fabrics like linen will wrinkle more than synthetic fibers like polyester,” Wang says. Natural fibers don’t have the built-in elasticity of synthetics, so once they crease, they tend to stay that way.

Load size is another major factor. “The larger the load, the more weight there is pressing down on the clothes to cause creases and wrinkles,” Wang says. A dryer stuffed to the brim doesn’t give items at the bottom much room to move, so wrinkles set in more quickly and more deeply.

Why Clothes Get Wrinkly in the Dryer

If you’ve ever wondered how and why clothes wrinkle, it comes down to chemistry. “Wrinkles form in fabrics due to the breaking and reforming of hydrogen bonds in the fibers,” Wang explains. When fabric is exposed to moisture or heat (such as in the washer or dryer), those hydrogen bonds break, allowing the fibers to rearrange. “Then as the fabric dries or cools, new hydrogen bonds form, locking the fibers in their new positions and creating wrinkles if they’re crumpled up," she says.

Wang says this process is why timing matters so much. “Wrinkles form as clothes cool off, so letting clothes cool and sit in the dryer will also lock in the wrinkles and creases if they’re left bunched together.” And if the dryer is full? “Wrinkling is also exacerbated with pressure, so if you have a large load in the dryer, the weight of the load will worsen wrinkles," she says.

The takeaway is that wrinkles don’t happen just because your clothes are dry. Rather, they can happen because they cool in the wrong position. Your job is to catch them before that happens.

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Even if you have the best of intentions, it’s easy to forget a load now and then. The good news is you don’t need to drag out your iron or steamer. “If your dryer has a steam function, you can try running a quick steam cycle,” Wang suggests. “The moisture and heat will help release the wrinkles so you can have another opportunity to catch the clothes before they wrinkle and remove them from the dryer and fold or hang them up.” This method works because the added steam temporarily relaxes the fabric fibers, breaking the newly formed hydrogen bonds and allowing clothes to return to their original shape.

If your dryer doesn’t have a steam setting, you can mimic the effect with items you already have at home. “You can toss a clean, damp towel in with a dryer sheet and re-run a dryer cycle,” Wang suggests. The damp towel adds steam, and the dryer sheet adds smoothing power. “The moisture in the towel will help release the wrinkles (and trigger the moisture sensors in the dryer), and the heat-activated conditioners in the dryer sheet will help smooth any wrinkles and help prevent new ones from forming as clothes dry," she says.

You’ll also fight off a problem many of us experience during the winter. “Dryer sheets also help fight pesky static cling, which is especially prevalent in the cold, dry conditions of winter,” Wang adds. Most loads only need about five to 10 minutes with this method—definitely not a full cycle—so it’s quick enough to do, leaving you more time to fold or hang items.

How to Prevent Wrinkles from Forming in the Dryer

If you want wrinkle-free results without the stress of racing to the dryer the moment it stops, a little prep can go a long way. “To prevent wrinkles in the first place, toss Bounce dryer sheets in with your wet clothes at the beginning of the dryer cycle,” Wang says. She explains that the sheets have heat-activated conditioners to help prevent wrinkles, reduce static cling, and soften fabrics. Just make sure you use the right amount for your load by reading the package directions.

Other small habits also help to prevent wrinkles in the dryer. These include:

• Avoid overstuffing the dryer.
• Remove items as soon as they’re done.
• Give each piece a quick shake before folding.
• Dry similar fabric types together so lighter items don’t get crushed by heavier ones.
• Use dryer sheets that help reduce wrinkles.