*no fever?

I think either temperature or fever is acceptable. But I think
"You don't have a temperature." is more natural English.

any chance it could be added as a second translation? [I personally never heard temperature used like that :P could be a british usage? (and google returns more results for fever :PP)]

Half a million Google hits is enough for me. :-P

I'll add the fever version as an alternative translation though.

Is there any difference in severity between "temperature" and "fever"? From what temperature up can you call something a "temperature" or "fever"?

I would say that anything above normal blood temperature is "a temperature" but it has to be /significantly/ above to be called "a fever".

To put it another way, if your child had a temperature you might let him have a day off school, but if your child had a fever you'd probably take him to the doctors.

I see, thank you for the explanation.

In Dutch we differentiate between "verhoging", which is a temperature up to about 38°C, and "koorts", which is above 38°C, so I guess it would be possible to translate "a temperature" with both, right?

Yes, although by the sound of it "verhoging" ~= "temperature" wouldn't be that far out.