Tog/tɑːɡ/ Definition 1 of 3Pro Tip 1/3Measure Warmth Used to describe how warm bedding can keep you, not for clothing. Check the tog for a cozy night's sleep. Pro Tip 2/3Winter Duvets Higher tog values mean more insulation — ideal for colder seasons. A 13.5 tog duvet is perfect for winter. Pro Tip 3/3Summer Comfort Choose lower tog values for a cooler and more comfortable sleep in summer. I switched to a 4.5 tog duvet for the heatwave.