Yes that's the only negative about Kentucky Bluegrass unless your yard is shaded and you water properly.
Oh, it's dying from heat, not cold. Out here the bermuda dies off in the cold and we over-seed winter ryegrass.
Most of ours is hybrid fescue, but it gets invaded by bemuda. If you keep the fescue tall and seed in the rye, the bermudagrass stays under the radar.