Warm up time for amps

My amps ( I have many but as an example in this case Bryston 7b3's) seem to take a good 45 minutes to reach best sound. My question is ... how do I warm them up quicker? Is playing them on a revolving loop or shuttle BEFORE my listening starts the only option? If that is the case does playing at low volume achieve the same results, and/or does playing louder speed things up, and if so presumably the louder, the quicker in proportions?
And in that box, is the ambient temperature (eg summer or winter) a factor? To me, it should make no difference with all that stuff going on inside a confined space,  but someone will tell me otherwise? I could rig up small fan heaters to blow for ten minutes? If it cuts down warm up time by half for example it may not be such a  stupid or strange idea as I think it might be, as it would increase the proportion of "enjoyable" listening time substantially.
I could even be super smart by putting timers on the fans (which in case anyone points out a supply contamination issue ... could be on a different circuit entirely
The amps are rarely switched off.
This issue does frustrate. All that expensive kit not performing at best for a period ....