See:
Maple (Acer spp.) - Leaf Scorch
Note: Hydrangea macrophylla is considered a heavy water user and wilts easily under water deficit and/or high heat, though differences among cultivars exist.
Wilting of these Hydrangeas during the June 2021 heat dome.
Jay W. Pscheidt, 2021.
Sunburn results in necrotic tissue on both flowers and leaves if not water during heat stress events.
Jay W. Pscheidt, 2014.
See:
Maple (Acer spp.) - Leaf Scorch
Note: Hydrangea macrophylla is considered a heavy water user and wilts easily under water deficit and/or high heat, though differences among cultivars exist.