This week we have had temperatures in the 90sF, which is unusual for here. I know other parts of the country have experienced even higher temperatures. Now that temperatures on our end are getting back to normal we will start shipping the orders that have been on hold for a while. I can only guess that plants in USPS transit are kept in reasonably temperature-controlled environments for most of their journey. If you are concerned about the package containing your plants being left in direct sun in hot temperatures for an extended period of time, you can always request that the package be held for pickup at your local post office, which is probably air-conditioned. There is no extra charge for that service.