Beautiful pups - they will teach you many, many things and delight you as the training goes! When we had our girl in puppy training we (and the trainer) learned that "drop it" works better than "leave it" because usually they already have whatever they shouldn't have before you can issue the command. "Drop it" still works so glad we found it. Best of luck with your adorable pair. They should not have trouble with the heat; mine lays on the porch in the sun when the temperature is hovering around the high 90's, while her companion, a basenji/sheltie/collie mix, races for the A/C when the temperatures start rising.