Some damaged plants have already dropped their dead flowers and some of their brown leaves. However, removing the remaining dead leaves will not only improve appearance but will stimulate new growth. Where there are several brown leaves connected by a stem, the whole stem should be clipped off just above the first undamaged leaf. This will stimulate the most new growth.
Trees may need professional pruning by an arborist.
Of course the most important thing to do if we have similar 100 degree plus heat waves is to keep plants well irrigated. Container plants may need more than once a day watering. I am concerned about trees that showed no damage having major damage later with dry weather in the 90s. Trees which are beyond any irrigation system are particularly vulnerable. Some deep watering of trees is very advisable.
Container plants can be temporarily moved to shadier locations.
Covering plants with white cloth-like sheets will not only provide shade but reflect the light and heat. Even newspaper or other white paper can be used.