If you are suffering from the heat, you may also be wondering if your trees are suffering, too. Bert Cregg, a professor of horticulture and forestry at Michigan State University, says you probably do not have to worry about the well-established trees in your yard during heat waves. But younger or more recently planted trees could use a little extra help. He recommends thorough watering, once a week, near the base of any trees that were planted in the past year or two.