Usually, bare root plants are supplied with wrapped roots - that might be burlap or fabric or some plastic, so hopefully that's what they've done. When you get them, soak the roots in a bucket of water for at least 2 hours, then plant out. If its a good supplier, they may come with instructions, and these often tell you how long to stand them in water for.
UPDATE: Sorry, I hadn't quite grasped the situation, I thought you meant you couldn't collect them from wherever they were waiting. As you've got them already, if you mean, by wrapped in plastic, each one is contained within a plastic bag from top to bottom, they should be fine left outside in a shady spot. If only the roots are wrapped, then can you find somewhere to heel them into the ground? That just means digging a bit of a hole and burying the roots in it temporarily until they can be planted permanently -its often done if the weather isn't right for planting when the plants are delivered. Best done in a shady spot.