Nothing to do with Rhod Gilbert’s comedy sketch!
I have a 15 tog duvet in winter, but there are times when I’d like to be warmer. If I were to put, say, a 5 tog duvet in the same duvet cover as my 15 tog duvet, does that make it 20 tog, or does tog ratings not work like that?
I’ve never seen a duvet with a tog rating above 15, but is that because a) it’s not possible or b) because manufacturers don’t think there is a market for duvets of higher than 15 tog?
What about really cold countries, like Canada or Scandinavian countries, what is their highest tog duvet? (Assuming they use duvets there, they might prefer sheets and blankets)