Dark red new leaves or old ones? How old is the plant? Potted or in the ground? Is it close to any walls, fences, sidewalks or driveways? What is the name of the rose? You've asked two questions which can't be answered fully without more information. In short, yes, it's been HOT here in Southern California and yes, this kind of heat can cause small flower buds or even the plant to stop blooming until it cools off. The new flowering growth is very soft and it will wilt when it is hot. The plant sweats more water than it can drink, very simply. Red foliage can be normal for the rose's genetics, but without knowing WHICH rose it is, no one can say for sure. Kim

IF it is a freshly planted or new-this-year rose, shading it with something (umbrella, shade cloth on some sticks) will reduce stress and likely prevent that drooping. Next year when its root system is more established, it will be better able to handle summer heat.

It sounds like heat and water stress. Give it some shade any way you can and keep watering it well in these hot dry days. Even some of my older more established roses have wilted a bit on very hot afternoons and I haven't been nearly as hot as you and our humidity is very high. That humidity doesn't seem to help them at all and I still have to water frequently.

Is that dark red foliage new shoots coming? A lot of roses have reddish new growth that greens up as it matures fully.