Most people agree that doublets and hose were made with wool on the outside and linen on the inside.
Are there any evidence that confirm such belief? Any guild documents, findings, etc? Do we have any evidence contradicting this theory, allowing linen-on-linen doublets and hose?
Just looking over that wikipedia link, I'm seeing a lot of references to British monarchal eras and Highland fashion. So it could be that this was an item primarily prevalent in England and Scottland.
England is not exactly famous for its sunny climate, and average temperatures there even in the summer appear to be a few degrees cooler than in Poland (where you are performing this re-enactment?). Where I come from in the middle of the Continental USA, it would be considered downright cold. We regularly have days a good 40 or 50 degrees F hotter.
Scottland is even colder, murkier, and damper. A wool lining would be highly desirable there, both for its insulating properties, and for its wet-weather behavior.
Also that area was pretty much the wool-production capitol of Europe. So the material would have been much more plentiful (and cheap) than it would be most other places. Most Scottish nobles could probably skim it for free from their own estates.
So I don't personally find this all that unlikely. However, garb in Poland may have been different, and summer garb in Spain or Greece was almost certainly different.
For my money, unless you can import Scottland's climate for your re-enactments too (perhaps run them in the spring or fall?), I wouldn't take versimlitude to quite that extreme. If you are sweating like a pig due to overheating in a non-historically accurate climate, that's a bad re-enactment too, isn't it? Then again, I'm not much of a SCA or LARPer, so I don't know the culture like you do.
I'm very much late for this "party", but Portuguese nobility wore doublets (or their precedents, as the doublet only hit full force in the last quarter of the 14th century and many men still wore the older surcoat) made of linen, silk or fabrics woven with both linen and silk. There were wool fabrics too, but that was more common for winter.
Naturally, poor folks might have a single outfit to last them a whole year, which would mean a linen chemise and everything else wool. But Portuguese imagery show peasants working the fields in the summer wearing only white chemises as a way of dealing with wool vs. hot Portuguese summers.
In conclusion, I am not so sure about the fabrics worn by the men in the lower ranks of an army, but nobles would have definitely worn linen (with or without silk depending on their social standing) doublets (and surcoats).
