Sher, I'd like to suggest waiting until evening to plant. This way they get a better head start before having to deal with the sun. Another suggest ion is to keep an eye on the weather and, if possible, plant on the last ni ce day before a few cloudy / rainy days.
KEEP THEM WATERED. Although they may seem to have a nice root ball, the truth is that most of the hair roots ... the ones that do the actual feeding ... will have been damaged or severed. By the end of this season, the hair roots will have re-established themselves.
Let us know how things turned out, eh?
Bill