It is possible test kits are exposed to freezing temperatures in transit, but this will not affect the performance of the included tests. When you receive your Cold & Flu Rescue Kit, store it between 2-30°C. If the solutions are frozen let them thaw slowly. Ensure the solutions have warmed to 15-30°C before using them to est. Do NOT expose the kit to a heat source to speed the warming process. For convenience, it is best to keep the kit at room temperature and not refrigerated.