We use the shipping method that you select at checkout. Cold packs are included with vaccine orders at no extra charge. However, we strongly suggest selecting NEXT DAY shipping for vaccines. When selecting GROUND SHIPPING or even SECOND DAY SHIPPING, vaccines could arrive warm, especially in the warmer summer months. Vaccines are non-returnable and non-refundable. Please be sure you are selecting the shipping option that you are comfortable with.Vaccines are only shipped Monday through Wednesday to prevent them from sitting in shipping facilities over the weekend. If your order is placed after 2 pm on Wednesday then regardless of shipping option selected the vaccines will not be shipped until the following Monday to ensure the greatest chance of them arriving cold.