The pic shows rot. The leaves turn soft, then eventually dry out.
The solution to saving your plants is to immediately dry them. Dig them out of the soil, then gently remove as much soil as possible so that you are exposing the roots to the air. It would not hurt them to dunk in some cool water a few times to remove as much dirt as possible, but if you do this, the plants need to drain on dry towels so that the extra water is gone within about an hour.
Once the plant has dried for a few hours, carefully pull off all of the leaves that show signs of rot. Hopefully, the central stem of the rosette will not show any sign of rot. At which point, let the rosette dry for a few days out of the hot sun(breezy shade is ideal), a week is certainly OK. Then plant in dry medium with good drainage and do NOT water for several weeks - misting lightly is OK once a day or every couple of days. Watch closely. You want to be able to distinguish between rot and the plant shriveling for lack of water. Semps can survive for months without being watered, as long as it is not too hot. Paradoxically, during hot periods, they are sensitive to too much water, especially if there is any physical damage to the plant.
Good luck and let us know how they do for you.
IF the stem shows sign of rot and you need to keep the plant, you will need to do surgery. Generally speaking, rot on the stem will spread and kill the plant. Cut out any sign of rot on the stem, once you have removed all rotting leaves. Dusting the stem lightly with powdered sulfur will help prevent any infections of the wound, but should not matter too much if you dry the cuts before planting.
Action is needed promptly to stop rot. Mostly likely the plants sustained some sort of damage during the handling or moving, then were exposed to too much water/moisture. The heat does not help. Your zone and growing conditions are generally Ok for Semps.
