[AusNOG] Cable length limits?

[Paul Gear]

Hi all,

I'm working on a project involving a new facility being built in 
Townsville.  A consultant on the project mentioned to me today that he 
had heard some discussions which suggested that the maximum distance of 
90m on a Cat5e/Cat6 run applies to environments where the ambient 
temperature is around 20 degrees, and that higher temperatures can 
actually require lower length limits.

Can anyone confirm or deny, and/or point to some relevant references?  
Google seems to have some relevant hits, but discerning the wheat from 
the chaff is tricky - many of the first few hits for the searches I did 
were from companies trying to sell higher grade cabling.

Thanks in advance,
Paul