the silkies i had have been fine out in the heat.... and as long as they have shade and plenty of water and MAYBE a frozen water bottle in their shaded area in the afternoons, they should be fine outside....
as far as the pox thing, my silkie had it... i was for sure he was going to die... and he pulled through... no meds just let nature take it's course.. it was pretty gross at times... and he had a second outbreak later.... but i did read that you don't want them near your other birds because it can be spread through the scabs falling into the drinking water... i didn't do a LOT of research on it, but if that is what it is, they might pull through...
i've had another funky something running through my flock, hitting random birds... MOST have recovered.. not the smaller chicks though... but they get this infection and swelling JUST on the right side of their head around their eye..... to where that side swells up like 3x as big as normal.... one i treated with antibiotics, and some poultry drench... the others i didn't treat... the outcome was about the same...
most hatcheries do not vaccinate unless you pay extra... and the ones you buy from the feed store are normally not vaccinated...
oohhh and by the way... i glanced somethign about poly vi sol... i've never used it, but this poultry drench... it is awsome... i had a chick that i expected to be dead by morning so i had put her in a box on top of the the cage to die without having everyone step all over her... i sawthe bottle sitting there from trying it on the bog girl a week prior... i decided to try it so i forced a dropper into her and set her back in the box... next morning she was running around on the bathroom counter... she jumed out of the 12" tall box and down 2.5' to the counter and was having a ball running around... i was like WTH!?!?! you were sposed to be dead.. lol... i don't know where it came from, ke_ben let me borrow it and then ordered me a bottle on his next order so i could have it on hand...