There is such a thing as hot-water pastry, but it is a thing unto itself and (my opinion) not nearly as good as regualr pastry made with ice-cold water and a gentle hand. Think of it this way... for many generations before us pastry makers have been using ice-cold water. There must be a good reason!
When I need to bang out a pie in a rush I still use ice-cold water and short the resting time. The pie dough might be more difficult to roll and shrink more but the fat globules are intact enough to still make the crust reasonably flaky.
In yeast breads ice water delays the activation of the yeast, allowing a longer period of time for the amylase to break down into sugars. When the yeast finally wakes up it begins to feast on sugars that weren't there the day before. Sugars remain in the final dough lending itself to a more caramelized crust. Only for lean doughs. The complex flavor would be lost in an enriched dough or one with other inclusions.