If you are looking for a duvet or duvet cover bedding, you will probably want to consider how thick or warm you want your duvet.  If you live in a very warm climate, it is likely that you will want a lighter weight duvet.  However, if you live in an area with a long cold winter, a more heavyweight duvet may be the better option.

Manufacturers will typically  rate the performance of duvets based on their tog rating. This allows you to pick a duvet that is season appropriate. The higher the tog rating is,  the heavier the duvet.  Some manufacturers are even marketing  duvet sets that include two duvets; one that is around 4.5 tog and a heavier one of 9.5 tog. Using them alone or putting them together, you can have a duvet for every season.