Have you ever heard of frozen shirts? It’s a silly prank where you soak a shirt in water and stick it in the freezer to make it stiff as a board! My friends and I tried it last week, and I couldn’t wait to tell everyone how long the whole freezing process took.

What You'll Need

Before you start, here’s the stuff you’ll need to pull off this icy prank:

• An old shirt that you don’t care about wrecking (ask your parents first!)

• A big mixing bowl or sink to soak the shirt

• Water, and lots of it

• A freezer that goes below 0°F (-18°C)

Prep Time

The prep part is easy but messy—and that makes it super fun! Just soak your shirt completely in the water. You can wring it out a little if you want, but leaving it dripping wet will make the shirt freeze harder later.

Once it's soaked, lay the shirt flat in the freezer so it freezes evenly. Make sure to tell everyone not to eat that soggy blue Popsicle stuck in the back!

Read more: The Epic Guide to Frozen T-Shirt Contests

Freezing Time

After all that splashy setup, here’s the part you really want to know: how long do you have to wait before the shirt is frozen solid?

In a normal kitchen freezer kept around 0°F, it takes about 2 to 4 full hours for the sopping wet shirt to freeze into a stiff board. But here’s a timeline so you know what to expect:

• After 1 hour: Shirt begins to stiffen but is still bendy

• After 2 hours: Shirt hard to bend and starting to freeze solid

• After 3 hours: Shirt is very stiff and frozen mostly through

• After 4+ hours: Shirt rock solid frozen!

The exact time depends on a few things. Like if you have a powerful freezer that gets colder than 0°F, it’ll stiffen up faster. Or if you really soaked that shirt with a ton of water, it’ll take longer to freeze it all. Thicker shirt fabrics like flannel hold more water too, so they may need the full 4 hours versus a thinner tee.

The best way to check if your shirt-sicle is done? Try bending it! If it’s still floppy and flexible, leave it in longer. Once it cracks and snaps instead of bending, you’ve reached maximum frozen-ness!

Using Your Frozen Shirt

Now for the best part: what kind of arctic antics can you get up to once you have a fully frozen shirt? Here are some chilly ideas:

• Lean it against someone’s door so it falls on them when they open it

• Prop it up and scare your family by pretending it’s a frozen person

• Use it as a cold pack for sore muscles or injuries

• Take silly photos with it and make up wild stories about how it froze

• Play soccer, hockey, Frisbee, anything with it! But throw gently...

When you’re done messing around, just leave it out to fully thaw. The stiff shirt will slowly melt back to normal over half a day or so (kind of like Olaf from Frozen!). Just have towels handy to wipe up all the drips.

The one thing you shouldn’t do is try to wear it before it’s thawed—having a frozen solid shirt snap back into place on you definitely won’t feel good!

The Frozen Shirt Challenge

If you really want to take this frigid fun to the next level, try a frozen shirt challenge with your friends! See who can freeze a shirt the fastest, or have a competition for the most creative melted shirt photo. You could even start a viral online challenge daring people to try freezing the craziest shirt designs.

Before you know it, everyone will be posting frozen shirt videos online or trying to beat your icy record. Just be sure to clean up all that meltwater so your parents don’t slip!

Read more: Are Frozen Shirts Safe to Wear After Being Thawed Out?

The Next-Level Frozen Prank

Once you master the frozen t-shirt, you can move onto a bigger prank using the same chilly idea: freezing a whole pair of jeans or pajamas! It takes way longer to freeze depending on what you use, but just imagine someone’s surprise when they open their dresser and find a pair of fully frozen pants waiting for them!

So if you soak some pj's overnight and freeze them at least 8 hours, you can scare your sibling into thinking an icy inanimate pair of clothing has raided their room.

The Long and Short of Frozen Shirt Science

Freezing shirts, jeans, or anything else may seem like magic, but it’s really just simple science in action. As a quick reminder, here’s what’s happening:

*Water has special properties that make it expand and crystalize when it freezes. That's why ice floats!

*When your shirt gets completely soaked in liquid water, some remains trapped in the shirt fibers even after wringing it out.

*The super cold freezer temperature causes the leftover water to freeze and expand as it spreads through the fabric. The ice crystals lock the fibers in place, stiffening your once floppy tee.

*Let it thaw, and the process reverses: the shirt goes back to normal!

So now that you know the frosty formula, go out there and freeze some shirts! Try timing different tees, jeans, and jackets to see how the material changes the freezing time. Just be sure to share those hilarious frozen fashion fails—or epic icy pranks –with the rest of us here online. Happy freezing!