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
The tubes don’t mind the heat too much. The passive components like electrolytic capacitors would prefer it a little cooler. Although if you’ve been doing it for 40 years in that cabinet, with a fan, you’re probably fine. Just don't tell them that if you ever make a warranty claim.
It takes very little air flow to cool a chassis significantly. I've been doing it since the 70's. A couple of 12v 60mm PC cooler fans running on 3.5v are completely silent and cool the internal chassis from 50°C to 30°C on my tweeter PrimaLuna PL-5. Ditto a 100mm on midrange VTA M-125s.
PL-5: http://ielogical.com/assets/WinterBlues/PL5_Fans.jpg
M-125: http://ielogical.com/assets/M-125/BindingPost.jpg - note fan under tubes at front.
Thank you one and all for weighing in...
As an aside, I drilled a series of 1-1/4” holes in the upper back of the cabinet to provide convection venting....the two independent top drawers hide those holes.
I did install a small, quiet computer fan but it just couldn’t pull enough air to keep the gear from cooking.
(I was petrified to see millercarbon had replied.... I remain yet unskewered...love to witness the dust-ups he provokes.)
The temp gun is a great idea....
I use one of their component fans with front exhaust on my Parasound 5 channel SS amp. They have other fans for cabinets.

https://www.acinfinity.com/quiet-cabinet-fans/
Wow, those fan solutions are very inexpensive. Imagine if they were sold by Synergistic et al?