A bit of a niche really, water-based pillows are relatively rare but worth a mention. There are two main types of water pillow: ‘cooling pillows’ or mats like the Chillow pillow and 
water pouch pillows like the Mediflow range.
Water pouch pillows like the Mediflow claim to have superior comfort and pain relieving properties thanks to the user-filled water pouch which supports a more normal polyester microfibre layer which floats on top. Water pillows are adjustable in height by changing the amount of water used.
Comparing the two main water pillows, the Mediflow Waterbase Pillow is a proper pillow whereas the Chillow pillow is a mat which you sleep on or place over your existing pillow. The Mediflow was apparently the world’s first water pillow and as such is the most popular in the UK and in the US. It offers orthopaedic pillow support for neck pain as well as cooling – read our review here.
Cooling water pillows are those which have a foam layer which is saturated with water which helps to diffuse heat. These can be useful for those who suffer from hot flushes, night sweats or otherwise get too warm at night. Alternative ‘cool pillows’ are also now available so you don’t have to have a water-based pillow. These use material technology to ensure the fibre they use dissipates heat much quicker than cotton and are well worth a look. Try the ‘REM-fit Snow Pillow’ for example which uses ‘ice yarn’ – review here.
- Pros: Water pillows have customisable support, height and firmness, – you can add or remove water from the pillow. It shapes itself to contours, offers good pain relief, especially for back and neck pain, offers cooling.
- Cons: The water can make them heavy and sometimes noisy if there is an air pocket, fairly expensive, questionable durability, will need adjustment until you find the right water fill level.
Pillow advisor summary: Water-filled pillows are only really worth a go if you are looking for night time cooling, pain relief or extra support.