If you’ve followed directions, you are not panicking at this point. The biggest danger in your current circumstance, and the thing that will probably end up killing you is a lack of air. Popular Science theorizes that a healthy adult might have around five and a half hours worth of breathable air available. Just how long you’ll last depends largely on the size of the coffin, your own size and just how many of those panic attacks you had before you finally calmed down.

You should be able to add a bit of time to the clock by taking slow, deliberate breaths. If you come to realize — and accept — that you’re basically done for, you should be able to take solace in this, at least: It probably won’t be the most painful death in the world. It’s no great way to go, but you’ll lose consciousness before you actually die. Good times.

Let’s say you’ve decided to go for the breach and attempt to climb your way out of your grave. Let’s say, somehow, you’ve managed to split open the lid. Let’s also say that, by some incredible chance, you haven’t immediately suffocated and are on your way to freedom. Well, you’d best hope it hasn’t been raining lately, otherwise all that good luck and enterprise is going to be for nothing.

Science time: Soil becomes denser when it’s wet. Okay, that’s not exactly astrophysics, but it’s going to be pertinent when you’re buried in earth. If the soil has been soaking up a load of water recently, there’s a decent chance that you won’t be able to dig through it. Light, dry soil is your friend. Naturally, the deeper you’ve been buried the tougher it’s going to be, too. Take a look at the Noble Research Institute’s cross-section of the Earth: It should give you a good idea just how tightly packed it becomes once you get a few feet down.

So how did the people who survived actually make it out? Well, as we’ve seen, it does occasionally happen that someone is buried close enough to the surface that they can claw their way to safety, while the good old-fashioned knocking method has worked for others. In the vast majority of instances, however, concurrent events on the surface have led to the rescue of the mistakenly entombed.

A living newborn was exhumed in China in 2015 after doctors questioned the decision of the parent to bury their child after assuming it dead. A 3-year-old boy was rescued from his burial during the Irish potato famine after a gravedigger struck his legs, causing him to cry out in pain. In 1915, an American woman was saved from premature burial after her sister asked to open the coffin to see her one last time. If it happens to you, these are your best chances — hope that someone on the surface intervenes in some way.

But let’s say you are scared enough of premature burial to warrant actually taking precautions to prevent it happening. You’re going to want to do it in the most spectacular, downright ridiculous way you possibly can, right? Of course you are. Well, that’s where the safety coffin comes in. The concept is simple: Each coffin is specifically designed to allow the buried to call for help if they regain consciousness after burial.

A couple of them include bells placed aboveground so you can ring your way to safety if the worst should happen. Another allows the “deceased” to hit a signal device with their head to set off a signal or flag above ground, while a third, more modern version allows you to do the same with the simple push of a button. Invest in one of these and you’ll rest easy for the rest of your life — and beyond.