Short answer
Some do. A low-vapor membrane like vinyl holds more heat and moisture near your skin; a thin TPU membrane with a breathable face holds much less. If you sleep warm, choose a breathable protector, keep bedroom humidity at or below 50 percent, and let the bed air out in the morning before you make it.
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.
- Vinyl (PVC) protector:
- A waterproof cover made of polyvinyl chloride. Tough and wipeable, but it passes little water vapor and can crinkle.
- 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.
≤50%
Humidity
NIEHS advises keeping indoor humidity at or below 50 percent to reduce bed mites.
Warmth on a waterproof protector comes from moisture as much as from heat.
General information about mattress care, not medical advice. For allergy or asthma questions, talk with your doctor.
Why it happens
You lose water as sweat and vapor through the night. A breathable layer lets that vapor move away; a low-vapor layer like vinyl holds it near your skin, which feels warm and clammy. See sweat stains and yellowing for where that moisture ends up on a bed without a protector.
Fixes that work
- Choose breathable. Purple recommends "a stretchy, breathable mattress protector at all times."
- Lower humidity. NIEHS recommends indoor humidity at or below 50 percent.
- Air the bed. Pull the covers back for a while in the morning.
- Cool-touch fabrics and phase-change finishes help at first contact.
See breathable and cooling protectors and moisture and mildew under a protector.
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
- A Brief Guide to Mold, Moisture and Your Home · US Environmental Protection Agency
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.