DR. JOOHN | COOL3 14" Copper Gel Mattress in a Box – Medium Firm, 3-Layer Ergonomic Support, Cooling Pressure Relief, CertiPUR-US Certified (California King)
DR. JOOHN | COOL3 14" Copper Gel Mattress in a Box – Medium Firm, 3-Layer Ergonomic Support, Cooling Pressure Relief, CertiPUR-US Certified (California King)
Hero image 0 of DR. JOOHN | COOL3 14" Copper Gel Mattress in a Box – Medium Firm, 3-Layer Ergonomic Support, Cooling Pressure Relief, CertiPUR-US Certified (California King), 0 of 9

DR. JOOHN | COOL3 14" Copper Gel Mattress in a Box – Medium Firm, 3-Layer Ergonomic Support, Cooling Pressure Relief, CertiPUR-US Certified (California King)

|11 ratings

Key item features

  • Copper Gel Cooling Technology + Breathable Sleep Surface: Sleep cooler and more comfortably with advanced Copper Gel and our breathable Cooling-Breath cover. Copper-infused technology helps dissipate heat, regulate temperature, and reduce overheating for a fresher, more restorative sleep experience night after night.
  • Available in Twin, Twin XL, Full, Queen, King & California King – Designed for Every Sleeper: Choose the ideal size for your space and sleep style: Twin, Twin XL, Full, Queen, King, or California King. The 14"" COOL3 mattress contours to your body’s natural shape, helping relieve pressure points while delivering balanced medium-firm comfort and ergonomic support for a more restorative night’s sleep.
  • 3-Layer Ergonomic Support System for Pressure Relief: Engineered with three performance layers: Copper Gel, responsive Transition Foam, and a High-Density Stability Core. Together, they help promote spinal alignment, minimize motion transfer, and support your back, shoulders, and hips for deeper, uninterrupted sleep.
  • CertiPUR-US Certified & Fiberglass-Free Construction: Made with CertiPUR-US® certified foams that are low VOC, fiberglass-free, and free from harmful chemicals. Proudly made in the USA using premium materials designed to create a cleaner, safer, and healthier sleep environment for your home.
  • Removable Washable Cover + Relaxation Experience: Features a soft, hypoallergenic, skin-friendly cover with a modern wave-textured design. The removable cover is machine washable for easy care and long-lasting freshness. Includes exclusive QR access to a guided relaxation experience designed to help you unwind before sleep.

Specs

Bed size, California KingMattress comfort level, MediumMattress type, Gel MattressesMattress thickness, 14 inBrand, DR JOOHNMaterial, Copper Gel

About this item

Product details

Experience cooler, deeper, and more restorative sleep with the Dr. Joohn COOL3 14"" Copper Gel Mattress. Thoughtfully designed in the USA, this premium medium-firm mattress combines advanced Copper Gel technology with a 3-layer ergonomic support system to deliver balanced comfort, pressure relief, and full-body support throughout the night. The COOL3 construction features Copper Gel for cooling comfort and temperature regulation, a responsive transition layer that adapts to your movements, and a high-density stability core that promotes proper spinal alignment while reducing motion transfer. Together, these layers help relieve pressure on the back, shoulders, hips, and joints—making it ideal for all sleeping positions. Its breathable Cooling-Breath cover enhances airflow and creates a fresher sleeping surface, while the copper-infused foam helps reduce heat buildup for a more comfortable sleep experience. The removable wave-textured cover is hypoallergenic, soft to the touch, and machine washable for convenient maintenance and long-lasting freshness. Made with CertiPUR-US® certified foam, the COOL3 mattress is fiberglass-free, low VOC, and crafted without harmful chemicals—providing a cleaner and healthier sleep environment for you and your family. Available in Twin, Full, Queen, and King sizes, the Dr. Joohn COOL3 delivers modern comfort, cooling innovation, and reliable support in one mattress-in-a-box design. Includes exclusive QR access to a guided relaxation experience to help you relax and prepare for restful sleep every night.
  • Copper Gel Cooling Technology + Breathable Sleep Surface: Sleep cooler and more comfortably with advanced Copper Gel and our breathable Cooling-Breath cover. Copper-infused technology helps dissipate heat, regulate temperature, and reduce overheating for a fresher, more restorative sleep experience night after night.
  • Available in Twin, Twin XL, Full, Queen, King & California King – Designed for Every Sleeper: Choose the ideal size for your space and sleep style: Twin, Twin XL, Full, Queen, King, or California King. The 14"" COOL3 mattress contours to your body’s natural shape, helping relieve pressure points while delivering balanced medium-firm comfort and ergonomic support for a more restorative night’s sleep.
  • 3-Layer Ergonomic Support System for Pressure Relief: Engineered with three performance layers: Copper Gel, responsive Transition Foam, and a High-Density Stability Core. Together, they help promote spinal alignment, minimize motion transfer, and support your back, shoulders, and hips for deeper, uninterrupted sleep.
  • CertiPUR-US Certified & Fiberglass-Free Construction: Made with CertiPUR-US® certified foams that are low VOC, fiberglass-free, and free from harmful chemicals. Proudly made in the USA using premium materials designed to create a cleaner, safer, and healthier sleep environment for your home.
  • Removable Washable Cover + Relaxation Experience: Features a soft, hypoallergenic, skin-friendly cover with a modern wave-textured design. The removable cover is machine washable for easy care and long-lasting freshness. Includes exclusive QR access to a guided relaxation experience designed to help you unwind before sleep.
info:
We aim to show you accurate product information. Manufacturers, suppliers and others provide what you see here, and we have not verified it.  

Specifications

Bed size

California King

Mattress comfort level

Medium

Mattress type

Gel Mattresses

Mattress thickness

14 in

Warranty

Warranty information

Please be aware that the warranty terms on items offered for sale by third party Marketplace sellers may differ from those displayed in this section (if any). To confirm warranty terms on an item offered for sale by a third party Marketplace seller, please use the 'Contact seller' feature on the third party Marketplace seller's information page and request the item's warranty terms prior to purchase.

Warnings

Customer ratings & reviews

4.6 out of 5 stars
stars
11 ratings11 reviews
Includes global ratings and reviews
How item rating is calculated
Filtered and sorted results would be available on the new 'Customer ratings & reviews' page.
Sort by |

Showing 1-3 of 11 reviews

Aug 29, 2026
Reviewer name: AtypicalRussiaNJ
Top Reviewer
Item details
Bed size: Queen
Sold byDR JOOHNDelivered byWalmart
5 out of 5 stars
5 out of 5 stars review

Verified Purchase

Incredible, Premium, Luxury Quality:

I recently had to replace my guest bedroom mattress (a $1,500.00 mattress), after a devastating pipe burst inside the wall next to it. Water pooled directly into the center of the bed for several hours before I finally discovered the mess when returning home from work. In my search for a replacement, I looked specifically for high-end specifications that could mirror my damaged mattress. That search led me to the Dr. Joohn, COOL3, 14" Copper-Gel Mattress. Although this does not serve as my "main" everyday mattress, it is equally important to me. Both my mother and grandmother sleep on this bed when they come to stay at my home to spend quality time with me. Due to their advancing ages, it is absolutely vital that I have a supportive, high-quality mattress worthy of them—and the Dr. Joohn's mattress is definitely worthy and then some! They've both been thrilled with the comfort! And they're not easy to please! The 3-layer ergonomic support system—which combines advanced Copper-Gel, responsive "Transition Foam", and a High-Density Stability Core—provides the perfect medium-firm comfort. It does an incredible job of promoting proper spinal alignment and relieving pressure on the back, shoulders, hips, and joints, which is exactly what my mother and grandmother need for a pain-free, restorative night's sleep. They have also commented on how cool they stay throughout the night. The Copper-Gel cooling technology and breathable "Cooling-Breath" cover work together perfectly to dissipate heat and prevent overheating. I also appreciate that the wave-textured, hypoallergenic cover is removable and machine washable, making it incredibly easy to keep the bed fresh and clean between their visits. As someone who cares deeply about their health, knowing the mattress is CertiPUR-US certified, fiberglass-free, and low VOC gives me immense peace of mind. This USA-designed mattress-in-a-box delivers the exact same luxury feel and physical support as my previous $1,500.00, brand-name mattress. If you want a premium sleep experience that treats you and/or your loved ones like royalty, this is it!

Incentivized Review
Helpful?73T849OPWDDV20270771813
Aug 28, 2026
Reviewer name: Joseph
Top Reviewer
Item details
Bed size: King
Sold byDR JOOHNDelivered byWalmart
5 out of 5 stars
5 out of 5 stars review

Verified Purchase

Comfortable mattress. Beautiful color.

I am really impressed with this mattress from the moment we opened it. It expands nicely and there was no weird chemical smell.. so we didn't feel like we had to leave it sitting around for days. It has a nice balance of support and cushioning without feeling overly hard. The king size fits perfectly on our existing king bed frame and I really like that we don't need a box spring. It feels substantial and supportive once fully opened and looks great on the frame. Shipping was lightning fast, which was another big plus for something as large as a mattress. Between the comfort, easy setup, lack of odor and perfect fit, I'm very happy with it!

Incentivized Review
Helpful?73T849OPWDDV20270771813
Sep 2, 2026
Reviewer name: Emerick
Top Reviewer
Item details
Bed size: Queen
Sold byDR JOOHNDelivered byWalmart
5 out of 5 stars
5 out of 5 stars review

Verified Purchase

Mattress is absolutely amazing!

The Dr. Joohn 14 inch mattress is SUPER comfortable! Unboxing went super quick it did not take long to unwrap and set up in my bedroom. The shipping box it comes in is huge but not hard to open. I got the Queen size to fit my bed frame. The cooling gel part works wonders and prevents heat from being trapped. The mattress has memory foam which helps very much with lower back and body support. The outer material is soft and is removable to wash. I absolutely love it.

Incentivized Review
Helpful?73T849OPWDDV20270771813
Current price is $679.99
Price when purchased online
  • Free shipping
  • Free 90-day returns
Walmart Accident Plan by Allstate
Pro Haul Away Service

How do you want your item?

Try 30 days for just $1! Choose a plan at checkout.
How do you want your item?
Ships to
Arrives by Wed, Nov 18
.
Order within 13 hr 13 min
Sold by DR JOOHN
Fulfilled by Walmart
5 out of 5 stars
5 stars out of 5, based on 8 seller reviews(5.0)
Free 90-day returns
walmart plus

Try 30 days of Walmart+ for just $1!

T&C apply.