Have to agree with the other folks, the tree looks healthy, not water stressed at all, the new leaves do look a bit small, so maybe lacking some minor elements? I had a similar problem with some stunting on new growth, and solved it with, adding a fertilizer with just minor elements, like Zinc, Mg, Iron, Boron, Calcium and so on. if you do add something like this, start very very low, maybe 1/4 the recommended dosage. and with that heat, I would not do anything foliar at this time.