Best temperature for optimum tube performance


Is there an optimum temperature range in which tubes perform best?
I've been running tube amps/preamps for over 40 years and have always placed a small, quiet fan in front of them to prevent excessive heat build-up (a modified, two-door antique silver cabinet is where they reside).
I'm aware that electrical resistance increases in proportion to increasing temperature, but am I somehow decreasing the optimum performance of my tube components with this strategy?
128x128rettrussell
My three ARC amps (NOT TUBES) each have 32 output transistors and 3 cooling fans each.  So, 96 output transistors and nine cooling fans.  If I run them really hard for say an hour their temp never goes over 100 F.  Yes, I measure them with a BBQ probe remotely.

Although this does not speak to tubes directly, I would say that if the interior of your cabinet is close to the ambient temperature of the room
you are good to go.

A remote thermometer is very cheap and worth it if you are asking the question.  Start out cold and log the temps against time as well as noting room temp.

Let the snarking begin!

Regards,
barts
Put your gear in a ventilated wood rack and watch how much better your tube gear sounds.
Okay so look, all these replies and only ONE (mine!) actually addresses the OPs question: Is there an optimum temperature range in which tubes perform best?

No one else attempted so much as to even consider this question! Only me! And with the only answer that really makes any sense: check temps, listen, and see! Even explained how to do it!  

Only thing I got wrong, too optimistic. Assumed this being an audiophile site and the OP pretending to care, he (or someone, anyone!) might actually try and see. Right! That'll be the day! However, because I thought just maybe someone might actually BE an AUDIOPHILE they would maybe try.... and then the flying monkeys would rip him apart for having the temerity to say what he heard. For not being double-blind enough. For expecting something might or might not happen. For whatever. On and on. All the usual stories guys blather to avoid having to actually, you know, LEARN SOMETHING!  

For not lowering my standards enough, I do apologize. Will try to do better, by which I mean worse, going forward.  
The simple answer is no. 
Always provide gear adequate ventilation.   Especially tube gear and power amps.  They generate the most heat.