Try as they may, scientists have not been able to produce a single fiber to match the properties of wool. There is a common misconception that wool is best suited for warmth in cool conditions.  Scientific tests however negate this concept and consistently show that wool is ideal for bedding in hot, humid, dry, cold or wet conditions.  Before we go further into why you should choose a wool mattress topper and not a wool mattress entirely, here are some of the benefits wool provides:

  • Wool naturally repels dust mites and other little critters
  • The soft and luxurious natural Merino wool is completely de-barbed so it doesn’t feel prickly at all.
  • Wool breathes more naturally than synthetics & Wool is a natural fiber for comfort and quality.
  • Wool naturally wicks away moisture from your body to help you stay at a more consistent and comfortable temperature at night. You’ll stay dry with less perspiring and overheating so you won’t toss and turn so much.
  • Wool increases the duration of the most beneficial phase of sleep when you are totally relaxed and dreaming based on studies by the Woolmark® Institute.
  • Wool helps you maintain a lower more consistent heart rhythm by as much as 4%.
  • Wool facilitates a more comfortable individual body temperature so you fall asleep faster and stay asleep longer regardless of your partner’s temperature or preference.
  • Wool keeps you warmer in the winter because wool is one of the best natural insulators
  • Wool also helps to keep your skin cooler in the summer by wicking away moisture
  • Wool is hygienic and hypoallergenic – it effectively controls the growth of bacteria, mold, mildew and musty odors so it is great for allergy or asthma sufferers,

wool topper rolled up closeupHow is a wool mattress topper comfortable?

Wool has unique attributes, which give it superior performance to other fibers in a number of ways. Our bodies continually produce heat at a rate dependent on our activity level; this heat must be dissipated to the surroundings in the form of perspiration, at the same rate at which it is produced, to keep the body temperature constant. [Source 1]

When used in bedding wool creates a micro-climate that assists in regulating body temperature and humidity. The degree to which body temperature and humidity is regulated is known as “thermophysical” comfort, that is, a state in which the individual is free from thermal stress. Wool Mattress Topper & Blanket Sleep Study designed by P.R. Dickson used the subject’s own room and bed as control. Time-lapse photography monitored movement during the night to determine the sleep quality. [Source 2]

Dickson found statistically significant differences in the number of immobile periods, immobile sequences, and the percentage of the total time spent sleeping with the wool mattress topper and/or blanket compared with the acrylic surface. Again the wool mattress topper & blanket was proven to be the most restful surfaces to sleep upon.  The positive health effect of sleeping with wool is best illustrated by a study by Scott et al. [Source 3]

Of low birth weight babies. His study found that babies nursed while wrapped in lamb’s wool consistently showed a significant improvement in weight gain over and above those nursed by conventional methods using cotton.

Physical Properties of Wool Fiber

Wool’s comfort advantages have traditionally been attributed to the capacity of the fiber to absorb a significant proportion of its own mass as water. [Source 4]

Wool can absorb 33.9%of its weight in water compared to synthetics at .4% and cotton 8%. Researchers agree that more than simply absorb, wool fibers have the ability to buffer by reacting to the humidity level within the particular environment. As the humidity rises, wool will absorb and store moisture as required.

When the level decreases, the fibers release the moisture thus regulating the micro-climate. This property ensures that a damp, clammy feeling will never be experienced with wool. In this way, instead of the body regulating the micro-climate, the wool bedding acclimatizes the body, ensuring a healthier rest with an even heart rate and blood pressure.

Additional Wool Mattress Topper Advantages

Another advantage of wool over other fibers is its outstanding insulating properties especially when compared with synthetic fibers.

The unique three-dimensional form of wool allows it to trap small packets of air, thus giving it an insulating property. This property ensures that temperature changes are slow and gradual so that the bed’s micro-climate has time to equilibrate. Rapid changes in heat loss or gain would hinder temperature and humidity regulation.

Wool’s natural resilience is another property which aids in comfort. The pile of an underlay (wool mattress topper) will reduce pressure points and cushion the body. Tests using wool underlays with the elderly and bedridden patients in hospitals have shown dramatic differences between the performance of wool and polyester bed pads.

Patients on wool had significantly fewer skin problems than those of polyester pads. 775 of those on wool had no problems compared to 38% of polyester. Of those with decubitus (skin break down), only 8% had any problems at all for more than one month. Those that slept on polyester had 38% more issues and problems for a period of more than one month.

In addition, no patients on wool had renewal of skin irritation once the initial problem cleared up, while 14% had repetitive periods of irritation on polyester**. The health aspects of sleeping on wool continually outrank similar synthetic products.

The Flammability Performance of Wool and Polyester Mattress Overlays

An additional benefit of wool bedding is the peace of mind in knowing that wool is naturally resistant to ignition and is self-extinguishing. Perhaps the most dramatic demonstration of this was a trial developed to evaluate wool and polyester overlays to the British Standard B.S.7175. the ignition sources were, from one to six; a cigarette, 3 butane flames (the smallest of which represents a burning match) and 4 wooden cribs of various weights.

Results showed that the mattress assembly containing the wool underlay was capable of resisting ignition [Source 5], (wooden crib 16g) with no evidence of progressing smoldering. The polyester overlay however, when tested with a simulated match (ignition source #2) was found to act as a secondary source of ignition requiring extinguishing after eight minutes 10. The ignition sources are numbered relative to their propensity to ignite the test material. Wool with its unique physical properties is the ideal fiber for bedding applications.

It has been subjectively and scientifically proven from a number of perspectives that wool has the advantages over other fibers. Irrespective of whether wool is used for protection or comfort, its applications are suitable for conditions ranging from hot and humid temperatures to the harsh and freezing Antarctic.

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**Sample of 26 on wool underlays and 21 on polyester.


  1. How is a wool mattress topper comfortable? “Wool-Why is a wool mattress topper so comfortable?”, B. Holcombe, Proceedings of the 8th International Textile Research Conference, Vol V., Fibre assemblies ad product Properties, ed G.H. Cranshaw (WRONZ) 1990, 205-214
  2. Wool Mattress Topper & Blanket Sleep Study “Effects of a fleecy woolen underlay on sleep”, P.R. Dickson, the Medical Journal of Australia, January 21, 1984, p87-89.
  3. (Positive Health Effects from Wool “Weight gain and Movement Patterns of Very Low Birthweight Babies Nursed on Lambswool”, S. Scott , P. Lucas, T. Cole and M. Richards, Child Care and Development Group University of Cambridge and the MRC Dunn Nutrition Unit Cambridge, Oct 1980-Sept 1981.
  4. Physical Properties of Wool Fiber 4 W.E. Morton and J.W.S. Hearle, Physical Properties of Fiber, the Textile Institute Manchester, 1986 Edition.
  5. The health aspects of sleeping on wool continually outrank similar synthetic products 5”Wool Pile Sliver Knit Bedpan Evaluation at Franklin Park Nursing Home”, L.R. Mizell, W.H. Marsden and V. Butler, Summary report by New Market Outlet Section, IWS November 1974. 10CPB-99”The Flammability Performance of Wool and Polyester Mattress Overlays”, R. Woolin, J.L. Webb, IWS Technical Information Bulletin, 29 June 1987.