Mattress Fillings and Their Benefits - Temperature Regulation

More and more people are increasingly interested in what’s inside a mattress, particularly around temperature regulation, moisture control, comfort, and support, not just firmness or price.

By focusing on fillings such as wool, cotton, latex, foam, and gel technologies, we can better educate ourselves, and differentiate quality products from entry-level options.

This blog is designed to address common sleep concerns and ultimately drive more confident purchasing decisions.

Alpaca

• Softer and lighter than wool
• Superior thermal regulation
• Hypoallergenic (contains no lanolin)
• Luxurious, silky feel
• Perfect for natural softness without overheating
• Holds 25–30% of its weight in moisture
• Ideal for warm sleepers wanting a luxury feel

Bamboo

• Naturally breathable and temperature regulating
• Soft, smooth hand-feel similar to silk
• Wicks moisture away from the body efficiently
• Holds 10–12% of its weight in moisture
• Helps offset heat retention when paired with foam or gel-infused foam
• Often used as a top cover or comfort layer for cooling mattresses

Cashmere 

• Exceptionally soft and plush
• Excellent insulation while remaining breathable
• Lightweight & moisture-regulating
• Luxurious but less durable than wool
• Best suited as a comfort layer
• Holds up to 30% of its weight in moisture
• Luxury option focused on softness and comfort

Cotton

• Breathable & cool - allows excellent air circulation
• Hypoallergenic - suitable for sensitive skin
• Natural & chemical-free
• Lightweight feel
• Best for people who sleep hot or prefer a firmer, flatter surface
• Holds 8–10% of its weight in moisture
• Better suited to cool, dry sleepers

Latex

• Highly supportive & pressure-relieving
• Naturally elastic - responds quickly to movement
• Extremely durable and long-lasting
• Resistant to dust mites & mould
• Excellent for spinal alignment and back support
• Holds 1–3% of its weight in moisture
• Performs best when paired with breathable covers (wool or cotton)

Memory Foam

• Contours to body shape for targeted pressure relief
• Reduces motion transfer - ideal for couples
• Helps relieve joint and back pain
• Can retain heat unless gel-infused or ventilated
• Holds 1% or less of it’s weight in moisture
• Performance improves with ventilation, perforation, or gel infusion

Polyester

• Synthetic fibre designed for durability and affordability
• Lightweight with a smooth, consistent texture
• Low natural breathability compared to natural fibres
• Minimal moisture absorption; dries quickly but does not wick well
• Holds ~0.4–1% of its weight in moisture
• Often blended with natural fibres (cotton, bamboo) to improve comfort

Silk 

• Extremely soft and smooth
• Naturally temperature regulating
• Hypoallergenic & dust-mite resistant
• Lightweight luxury layer
• Used mainly for comfort rather than structural support
• Holds 10–11% of its weight in moisture
• Best used as a comfort layer rather than primary moisture control

Wool

• Excellent temperature regulation - warm in winter, cool in summer
• Moisture-wicking - absorbs humidity without feeling damp
• Naturally fire-resistant
• Resilient - provides gentle cushioning and long-lasting comfort
• Ideal for all-season sleeping
• Holds 30–35% of its weight in moisture
• Excellent for night sweats and temperature balance

Foam

• Lightweight and affordable
• Provides basic cushioning and support
• Available in multiple firmness levels
• Less durable than latex or memory foam
• Commonly used in budget or hybrid mattresses
• Holds 1–2% of its weight in moisture
• Commonly layered beneath breathable natural fibres

Gel-Infused Foam

• Enhanced cooling compared to standard memory foam
• Gel particles help dissipate body heat
• Maintains pressure-relieving contouring
• Reduces heat retention for a cooler sleep surface
• Ideal for hot sleepers who like the feel of memory foam
• Holds 1–2% of it’s weight in moisture
• Cooler than standard memory foam, but still reliant on airflow
• Best paired with moisture-wicking natural fibres on top

Hemp

• Highly breathable natural fibre
• Helps regulate temperature and reduce humidity within the mattress
• Naturally antibacterial and mould-resistant
• Firm, supportive feel - often blended with softer fibres
• Holds 12–15% of its weight in moisture
• Naturally antibacterial & mould-resistant
• Durable, breathable fibre with a firm, slightly coarse feel. Commonly blended or quilted with softer fibres

The most effective moisture control comes from natural fibres, particularly wool, alpaca, and cashmere.

Foams, including gel mattresses, rely on airflow and cooling technology rather than absorption, making breathable covers and natural fibre layers essential for managing humidity.