What is a good comforter that is not hot for summer for your bed?

Question:I want to buy nice sheets and comforter set and a comfoter or I dont know if there is somthing that keeps you cool but comfy. a sheet alone is not enough? please help!

Answers:
Down comforters (and the synthetic down substitute) come
in different weights, so get a lightweight one for the
summer. I live in the SF Bay area and it gets cool and
foggy in July and August, we have a medium weight
comforter, its comfortable on most nights unless it gets
really hot, but it always cools off some in the night, so we
usually end up under it even in the summer. I make
duvet covers out of different types of sheets- for the
summer the T shirt sheets are really nice, they seem to
work well for any season, but we have some flannel for
the winter and some high count cotton for the summer.
I like usuing the duvet covers on just a comforter, no
top sheets, just a bottom one, it sure makes making the
bed a breeze, all you have to do is just shake out the
comforter in the morning and straighten the pillows and
its done.
(making a duvet cover is easy, just sew 3 sides of two
flat sheets together, after trimming them down a bit to
the measurement of the comforter, with a couple extra
inches at the bottom to turn under and either put buttons
and buttonholes, snaps or even velcro to close the bottom)