Head-to-head · Best Cooling Pillows

Purple Harmony Pillow vs Slumber Cloud UltraCool Pillow

Which is the better buy? Side-by-side on rating, price, strengths, and watch-outs — with the published ratings we averaged to get there.

The short answer

Slumber Cloud UltraCool Pillow comes out ahead by a narrow margin (4.4 vs 4.5). The gap is mostly about Hot sleepers who want maximum sustained cooling without fuss — buyers who don't need adjustable loft and prefer the soft, moldable feel of fiberfill over foam or latex. — read the strengths below before deciding.

Ranked #4 in Best Cooling Pillows

Purple Harmony Pillow

4.4

$179

Purple's Harmony pillow is an engineering-first take on cooling — instead of relying on PCM fabrics or gel coatings, it uses a 360-degree GelFlex Hex polymer grid wrapped around a ventilated Talalay latex core, giving you airflow through the whole pillow body. Reviewers consistently rate it 5/5 for temperature regulation. The feel is unique and not for everyone, but cooling performance is among the best in the category.

Strengths

— GelFlex Hex grid contains 1,500+ open-air channels for industry-leading airflow
— Ventilated Talalay latex core has thousands of pin-holes that further amplify cooling
— Three loft heights (Low 5.5", Medium 6.5", Tall 7.5") fit any sleep position

Watch-outs

— Most expensive pillow on this list at $179 standard medium
— Hex grid feel is polarizing — some find it cradling, others find it springy and odd
— Mesh cover developed pulls in Tom's Guide's month-long test

$179 · Check Price on Amazon Full review →

Higher ratedRanked #2 in Best Cooling Pillows

Slumber Cloud UltraCool Pillow

4.5

$154

Slumber Cloud built their reputation on Outlast PCM bedding, and the UltraCool Pillow is the flagship application of the same NASA-engineered fabric in their pillow line. CNN Underscored's tester said it was one of only two cooling pillows that actually cooled them overnight; Good Housekeeping named it Best Cooling Pillow. Pick it if you want pure cooling tech and don't need adjustability.

Strengths

— NASA-derived Outlast phase-change material absorbs, stores, and releases heat across the full night
— Named Best Cooling Pillow by Good Housekeeping and CNN Underscored for sustained overnight cooling
— Two firmness options (Soft/Medium, Medium/Firm) and three sizes including a 48-inch body pillow

Watch-outs

— Initial cool-touch sensation fades faster than some competitors as the PCM saturates
— 30-night trial is the shortest in this lineup — Saatva and Coop both run far longer
— Cooling works best without a cover; adding a thick pillowcase noticeably reduces the effect

$154 · Buy at slumbercloud.com Full review →

How they stack up

Purple Harmony Pillow

The most engineering-forward cooling pillow in this lineup — the Hex grid and ventilated latex deliver more raw airflow than the Coop Cool+ or Slumber Cloud UltraCool, both of which lean on surface cooling tech. The trade-off is feel: Purple's responsive bounce-back is unique. Saatva Latex shares a latex core but uses shredded latex (more conforming) while Purple uses solid latex with a polymer grid wrapped around it (more buoyant). Coolest on whole-pillow airflow, less cool on contact than the Cool+ or UltraCool. Cozy Earth Silk feels like a different category entirely.

Slumber Cloud UltraCool Pillow

Trades adjustability for pure cooling performance versus the Coop Cool+ — UltraCool's loft is fixed at the factory but the Outlast PCM is the most proven temperature-regulating fabric in the category. Cools more aggressively on contact than the Saatva Latex Pillow, but the Saatva's all-night airflow story is more consistent in a hot bedroom. Roughly tied with the Purple Harmony on overnight temperature; the Purple offers more responsive support, the UltraCool offers a softer, down-alternative-like feel.

Specs side-by-side

Spec	Purple Harmony Pillow	Slumber Cloud UltraCool Pillow
Material	Hyper-Elastic Polymer grid + Talalay latex	Down-alternative polyester fiberfill
Fill	Solid ventilated Talalay latex core	100% polyester fiberfill (adjustable on Adjustable model)
Cover	92% nylon, 8% spandex moisture-wicking mesh	100% polyester knit with Outlast coating
Cooling Tech	1,500+ air channels in Hex grid + pin-hole latex	Outlast phase-change material (NASA-derived)
Loft Options	Low 5.5", Medium 6.5", Tall 7.5"	—
Sizes	Standard, King	Standard 20x26, King 20x36, Body 20x48
Trial Period	100 nights (via Purple direct)	30 nights
Warranty	1 year	180 days
Loft Adjustable	No — fixed loft (choose Low/Medium/Tall at purchase)	Yes on Adjustable model; fixed on standard
Certifications	Hypoallergenic, dust-mite resistant	OEKO-TEX STANDARD 100
Care	Machine wash cover cold, air dry; spot clean core	Machine wash cold, tumble dry low

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