What is TOG? 31 May 2023 04:31 TOG stands for Thermal Overall Grade and is used to measure the thermal insulation of a product. The higher the TOG rating of a duvet, the warmer it is. Related articles Can I use my duvet in the dryer? What is fabric made from TENCEL™ lyocell fibres? I have spilt liquid on the protector, what do I do? How do I connect my Balmy Night Duvet to my All Seasons Duvet? What is TOG?