Naked necks are genetic. Naked necks are dominant, so one parent must be a naked neck for a chick to have a naked neck. Do you have a picture of your chick?
Probably not. Are yours bearded silkies? Beards reduce wattle size, and beards will show up in the first generation crosses. Some silkies also carry pea comb genes, which reduce wattle size and also show up in first generation crosses.
Most of the big, fluffy breeds like orpingtons aren't very heat tolerant. Leghorns and Andalusians are pretty heat tolerant, but they aren't very friendly. Yes, most breeds with large combs and wattles are heat tolerant.