The wilting, leaf curl and burned leaf margins are indicative of extreme water deficit (drought stress).
Go out right away and deep water a larger area as a rescue measure, not just next to the tree trunk. Set a sprinkler or soaker hose, or hand water with an open hose end, the entire area under the foliar spread, and a little more. You need to get a lot of water to the tree right away before the leaves dry up even more, past the point of no return. Try to achieve water penetration into the soil profile of at least six to twelve inches depth. Do that again the following day and then two or three times a week through August, then once a week through fall.