Slumber Cloud Core Mattress Pad Review

Sleepopolis may earn a commission on sales through our affiliate links in this article. This commission allows us to run our testing lab and continue to bring our readers the most comprehensive information on sleep and related products. See our disclosures.

The best mattress pads, notably thinner than the mattress toppers, are a fantastic way to add a touch of softness and comfort to your mattress. They sit on top of your mattress and beneath your sheets, and depending on the product, they can also protection to your mattress (though mattress protectors are even better at doing this).

I’d heard a lot about Slumber Cloud’s products and their out-of-this-world use of Outlast temperature regulation technology (developed by NASA), and wanted to test it for myself. Will the company’s Core mattress pad live up to the hype? Continue reading the Slumber Cloud Core mattress pad review to find out!

Editor’s Note: In early 2022, the Slumber Cloud Nacreous mattress pad rebranded to the Core mattress pad. Though this product was renamed, it still maintains the same quality materials and effective construction.

If you’re short on time, you can skip straight to my review summary.

Slumber Cloud Nacreous Mattress Pad

Slumber Cloud Nacreous Mattress Pad
Check Price

Accessories Details

Financing
Financing

Not Available

Who Is the Slumber Cloud Core Mattress Pad Best For?

Who I Recommend the Slumber Cloud Core Mattress Pad For

  • Hot sleepers: The Slumber Cloud Core mattress pad acts as a barrier between you and any heat-trapping mattress by using its Outlast technology. It works by storing excess heat until you need it, and regulating your temperature based on your body’s needs.
  • Couples with different preferences: The brilliance of the Core mattress pad’s Outlast technology is that it works on an individual level, so thermally varying couples can both sleep comfortably in the same bed.
  • Women experiencing pregnancy or menopause: Hot flashes won’t be completely eliminated with the Slumber Cloud nacreous mattress pad, but with thermoregulation, there’s a chance they’ll be reduced enough so you can sleep peacefully.

Who I Don’t Recommend the Slumber Cloud Core Mattress Pad For

  • Budget shoppers: The Slumber Cloud Core mattress pad has a number of special features that understandably drive up the cost to a luxury price point. Check out our Sleepopolis coupons page for our best deals on mattress products.
  • Light sleepers: Some of the more negative reviews say that the Core mattress pad has the tendency to crinkle beneath you. So, if you find yourself tossing and turning a lot and are easily disrupted at night, you might want a quieter option.

What Is the Slumber Cloud Core Mattress Pad Made Of?

The Slumber Cloud Core mattress pad is made from a 300-thread count 40% proprietary Outlast viscose and 60% cotton blend. The Outlast viscose material works to cool down hot sleepers, while the cotton maintains breathability and enhances a bit of cushioning. This higher thread count is intended to enhance durability and create a more long-lasting luxury product.

All of this care into the construction earned it an Oeko-Tex Standard 100 certification, meaning the Slumber Cloud Core mattress pad tested negative for hundreds and hundreds of toxic chemicals. This rigorous safety standard shows us that this product is sustainable and safe.

Slumber Cloud Nacreous Mattress Pad Review
Close up shot of the Slumber Cloud Core mattress pad materials.

More on Outlast Technology

As mentioned, the Slumber Cloud Core mattress pad is made with materials that use Outlast technology, which help to manage the micro-climate under the covers. Outlast is a special type of fabric technology known as PCM, or phase change material.

PCM works a bit different than moisture-wicking technology, which moves sweat and heat away from you and towards the exterior of the material. Specifically, PCM is designed to help you sweat less by storing excess heat from your body and then releasing it when your body temperature drops to prevent you from getting cold.

Slumber Cloud Nacreous Mattress Pad

Slumber Cloud Nacreous Mattress Pad
Check Price

Accessories Details

Financing
Financing

Not Available

How Does the Slumber Cloud Core Mattress Pad Feel?

This product has received a Gold+ Outlast-Certified Comfort Rating, which is the highest possible rating for heat storage and comfort. Overall, I found the construction and design to be very well done. 

First Impressions

While testing, I determined that the mattress remained close to its original firmness level, but there was a little more pressure relief due to the soft nature of the Core mattress pad itself. The increase in softness is similar to the level and type of additional softness you would  get with a thin summer style comforter. 

Slumber Cloud mattress pad on bed
Angled view of the Slumber Cloud mattress pad

Cooling

Unfortunately, a number of beds — especially many memory foam mattresses — hold in heat due to their materials’ nature. Even memory foam mattresses with cooler foams can still feel too warm for sleepers who generate lots of heat and/or are on the heavier side.

I wouldn’t describe myself as a hot sleeper. However, after sleeping on the Core mattress pad, I found it’s amazingly cool when you first get into bed. After a few minutes the materials begin to adapt to more of a temperature neutral feel, so you neither feel cold or warm. If you move to a new area on the mattress pad where you haven’t been lying, you’ll once again experience that initial cool feel again before the PCM kicks in.

Comfort

The feel of the material is equally impressive, so much so that my wife and I elected to forgo our fitted sheet so we could sleep in more direct contact with the mattress pad itself. The Core will still work fine with sheets on top, but for those who desire it, you can absolutely sleep in direct contact with the mattress pad.

Contrary to some of the more negative reviews on Slumber Cloud’s website, we found the Core pad didn’t rustle or make any noise. It was a true fit for my king size bed, and didn’t slide beneath me when I changed sleeping positions.

Slumber Cloud Nacreous mattress pad set up
Slumber Cloud Nacreous mattress pad on a mattress.

Slumber Cloud Nacreous Mattress Pad

Slumber Cloud Nacreous Mattress Pad
Check Price

Accessories Details

Financing
Financing

Not Available

Slumber Cloud Core Mattress Pad Sizes and Prices

Intended Mattress SizeCore Mattress Pad DimensionsCore Mattress Pad Price
Twin39″ x 75″$179
Twin XL39″ x 80″$189
Full54″ x 75″$219
Queen60″ x 80″$244
King78″ x 80″$254
California King72″ x 84″$254
Split King2 x 39″ x 80″$339

Slumber Cloud Brand Policies and FAQs

What is the Outlast technology used in the Slumber Cloud Core mattress pad?

Outlast is a special type of fabric technology known as PCM, or phase change material. It’s designed to help sleepers sweat less by storing excess heat from the body and then releasing it when the body temperature drops to prevent it from getting cold.

How do I care for my Slumber Cloud Core mattress pad?

As described on Slumber Cloud’s site, the cleaning process is simple, as you can machine-wash this product as you would with your own clothing.

Who is the Slumber Cloud Core mattress pad best for?

The Slumber Cloud Core mattress pad would most notably suit hot sleepers, as it’s built with special cooling technology. So, couples, pregnant women, and anyone who overheats at night should find lots of comfort here.

Surprising Cool Feel
  • Materials
  • Comfort
  • Sizing Options
  • Durability
  • Cooling
  • Style
  • Price
4.7

Summary

The Slumber Cloud nacreous mattress pad offers truly amazing cooling. Their use of Outlast’s phase change material technology provides impressive thermal regulation to sleepers who both sleep too warm or too cold. It’s not an inexpensive product by any stretch, however, for those sleepers who struggle to remain comfortable through excessive heat build up during the night, the price point will be well worth the added performance to your mattress.

Logan Block

Logan is the former content director of Sleepopolis. As content director, he reviewed new mattresses every week and curated the comparisons, best of pages, and video guides on the site. Logan perfected his method by personally testing over 200 different mattresses, so he’s not only able to discern the overall vibe of a specific bed, but to contextualize its feel within the bed-in-a-box market as a whole.