I'm the hot one in our bed so we have single duvets with different tog values. If we get a hot summer I usually remove my duvet and just have the duvet cover over me whilst the husband snuggles into his 7.5tog or whatever!
Added bonus is that there's no duvet stealing in the night anymore. 
Does anyone have a really simple diet plan?
Kellogg's have changed the recipe for Rice Krispies!
Talking to people in wheelchairs
)