Under the Covers with Russell Jelinek, Senior Director of Engineering

May 5, 2021 | Casper Editorial Team

When you think of an “engineer,” you probably think of someone behind a computer or wearing a hard hat. At Casper, there’s also such a thing as a mattress engineer. These types are the dreamiest of all engineers — and yes, they often sleep on the job.

Russell Jelinek, Casper’s Senior Director of Engineering, Quality, and Compliance, has been an integral part of the mattress revolution since he joined the Casper Labs team over 5 and half years ago. If you sleep on a Casper, he’s one of the reasons you sleep better at night.

In engineering Casper’s new Snow Technology, Russell applied the ins and outs of making a mattress that’s not too hot, not too cold, but just right. We dove under the covers to find out how we can chill out and become cooler sleepers.

You’re at a cocktail party. How do you describe what you do?

I try help people sleep! That’s what we do at Casper. Sometimes I say we’re “engineering comfort,” which means tying the physical and emotional experience of sleep and bringing it all together to an engineering specification. The challenge is taking this emotional idea of sleep — in which people are cushy and cuddly — and translating it to something I can actually specify, draw, and engineer.

What are some considerations that people might not realize go into engineering sleep products?

In terms of making a high-quality mattress, it’s all about durability. We want to make sure we’re getting the right firmness of every foam while making sure the mattresses survive their shipment to your door. We test all of our materials to make sure they pop out of the box with their full capabilities, and that such quality lasts for 10 years from now.

As for other tests, we also have to make sure everything has been “burn-tested.” There’s a test that we have to run that’s pretty straightforward, where we blast the side of the mattress with flames and take it away, ensuring it doesn’t catch on fire. (Most people don’t think about that one!)

How exactly does Snow Technology cool you down?

What we focus on is regulation. This means the snow is not actively cooling so much as it creates a sensation of cooling. When you touch the Snow, you might feel a cooling sensation to the touch. 

Go on…

Well, in designing Snow Technology,, we considered three phases of the sleep experience, and how to keep you cool in each.

The first phase has everything to do with what you feel when you first touch your mattress… emotionally. We want you to say, “Ooh this feels cold and refreshing. I can’t wait to get into bed.” 

We have a phase change material (PCM) in our Snow mattresses, where the first thing you feel when you put your hand down on the mattress is cooling. We did this through a gel pocket that goes from solid to liquid at 85 degrees. When it melts, it doesn’t increase your temperature; it just sucks energy away from your hand to produce an overall cooling effect. SCIENCE!

Then there’s the second phase, which is all about the first 15 minutes of falling asleep. We want to make sure you don’t have spikes in temperature in that time, so we work to optimize effectiveness and performance maintenance through textiles and fabric. We added a layer of PCM to the top foam to absorb the heat that is created from when you are lying on your mattress. As the top cover warms up, the heat flows into the PCM rather than into your body.  

The third phase spans the rest of the night. We don’t want to see spikes in temperature. As your body heats up the mattress in the microclimate, we want to avoid spikes. We have graphite strips that can handle a ton of heat. By varying the strips an inch deep, it makes a huge difference in sustaining temperature throughout the night and avoiding temperature spikes. It’s amazing how cool the mattress is to the touch. 

We also have perforation across all of our mattresses, which helps with the first and second phase.

Why do people get so hot in the middle of the night?

Honestly, a lot of this has to do with your covers, duvet, and sheets — and a lack of movement. I’m an engineer, so I’ll stick to the facts: too many covers is the biggest thing you can change. But everybody’s different, and some people run hot and need a cooler mattress. We have to consider that.

What kind of sleeper would really enjoy Snow Technology?

Snow Technology is for anyone who sleeps hot, or who’s ever woken up in the middle of the night sweaty. It’s especially good for people who like soft mattresses because softer mattresses will often make people feel hotter. More and more of your body comes in contact with a soft mattress. 

What do your engineer friends think of mattress engineering?

I think my engineering friends are always surprised by how much you can do to impact sleep. The impact we can have in tandem with ergonomics is really interesting. We want people to have freedom of movement because people change positions on average 20x per night. A lot of people still don’t get how fundamentally impactful better sleep can be on your entire wellbeing. 

I never thought I would work on mattresses. I used to do traditional engineering, more mechanical things. I’m often surprised by the complexity of mattresses — how much freedom you can have within the design, how you can create something that people have a strong emotional connection to. People look forward to their mattress and getting home to it.

Does engineering help you sleep better or make you more tired?

I sleep like a baby! Everything I design is based on something that I, myself, would also like and want to use. I don’t want to put out things that I don’t believe in.

Sometimes I’ll lay in bed and say, “Ugh, I need to adjust the design of this mattress.” It’s the most fun I’ve had as an engineer. 

If you’re looking to reemerge this summer as a cool new you, try starting with the Casper Cooling Collection. the Wave Hybrid Snow Mattress, the Nova Hybrid Snow Mattress, and the Hyperlite™ Sheets are sure to engineer better sleep (and cooler dreams). Build a bed that keeps you as cool as the other side of the pillow.