Please don’t! Nothing included in your shipment should go in the fridge. The dinoflagellates are living organisms that need a precise temperature range to live (63-77° F or 17-25° C). As soon as you receive the package, read and follow the instructions.
If for some reasons you are unable to fill your Dino Pet or Dino Sphere with the dinoflagellates upon delivery, take the dinoflagellate pouch out of the box and give it the lighting and temperature conditions as described in the instructions. The dinoflagellates can live in their pouch with the right conditions for several days.