Short answer
Breathable means the protector lets more water vapor pass, so less moisture is held against you. Cooling usually means a face fabric or finish that feels cool to the touch, such as lyocell or a phase-change coating. Purple recommends a stretchy, breathable protector at all times. If you sleep warm, look for a thin TPU membrane with a breathable face fabric and keep the bedroom humidity down.
Key terms used on this page
- Moisture vapor transmission:
- How much water vapor passes through a fabric or membrane. Higher means more breathable; woven microfiber encasings let air and water vapor pass freely.
- Phase-change material (PCM):
- A substance that stores and releases large amounts of energy as it melts and solidifies at a set temperature. The PFA says PCM in foam holds temperature near its melting point until its capacity is used up.
- TPU membrane:
- A thin thermoplastic polyurethane film laminated to a protector's face fabric to stop liquid. Casper lists 'Polyester with Thermoplastic Polyurethane' for its waterproof protector's top.
≤50%
Humidity
NIEHS advises keeping indoor humidity at or below 50 percent to reduce bed mites.
Two words do most of the marketing on protector packaging. Here's what each means.
General information about mattress care, not medical advice. For allergy or asthma questions, talk with your doctor.
Breathable
A breathable protector has a membrane and face fabric with higher moisture vapor transmission: sweat vapor can pass instead of sitting against your skin. Purple's warranty puts it in the brand's own words: "Purple highly recommends the use of a stretchy, breathable mattress protector at all times to protect your mattress and preserve your warranty rights."
Cooling
"Cooling" usually describes the face fabric: lyocell, polyester knits with a cool-touch finish, or a phase-change coating that absorbs some heat as you first lie down.
How to choose if you sleep warm
- A thin TPU membrane, not vinyl.
- A breathable knit or lyocell face.
- Bedroom humidity at or below 50 percent, which NIEHS also recommends for bed mites.
More on heat in do mattress protectors make you sleep hot?.
Sleep Sanitation's view
This section is our view. Sleep Sanitation serves Omaha, Lincoln and surrounding towns. Every visit includes dry vapor steam, HEPA vacuuming, UV-C light treatment, the built-in bed mite sensor on our JIGOO UV-C mattress vacuum and a moisture check before we leave. We take your protector off at the start of the visit, so you don't need to strip it first; wash it yourself per its care label while we work or afterward. The first mattress is $249. Call or text (402) 512-5658, or email info@sleepsanitation.com. Office hours are Monday to Friday, 9 to 6, and we return calls and texts on weekends.
Changelog
- 15 October 2026: First published. Sources accessed on this date.
Sources
- Purple Limited Warranty · Purple
- Dust Mites and Cockroaches · National Institute of Environmental Health Sciences
- Waterproof Mattress Protector: Materials & Care · Casper
Last reviewed October 15, 2026. Manufacturer specifications and care instructions change; check the current version for your exact model. This page is general information, not medical advice. How we source and check pages: editorial standards.