When I was at flybe I had a inciddent once where after 1 sector the cabin crew including myself became ill, felt sick and dizzy at the same time we complaines of strange smells in the cabin.
Crewing were informed and subsequently all our crew on that flight were told to report to hospital asap.
There we were tested for co2 posioning and found to have a high level than normal, but nothing dangerous.
I know of other crew suffering the same problems