I'm kind of surprised that the landscaper/nursery person did not provide a shade cover as part of the planting service.
Trees (and other plants) need to be protected from severe sun exposure as they will suffer transplant shock. Ideally, plants should be set in the ground under ideal conditions, like a nice, cool, cloudy week or two to give them time to recover.
There are products...antitranspirants (some call them antidessicants) which can be applied to the leaves to help the tree to not lose all it's moisture through the leaves but I think the temporary shade is a better idea.
