SIOUX FALLS, S.D. (KELO) — Shipped out orders of COVID-19 tests are beginning to arrive and the cold weather may be impacting how they arrive at your doorstep.

“Shipping in cold weather can affect it if it’s left outside in the elements, in a vehicle and it freezes,” Sue Reisch, RN at South Dakota Urban Indian Health, said.

The part of the tests that are arriving frozen are the vials of fluid.

“The fluid in the vial is a reagent that contains lab-made antibodies, so if you have COVID in your nostril you put the swab in the fluid and those antibodies bind to those antigens,” Michaela Sieber, CEO of Urban Indian Health said.

Health officials say you can still use the test even if the vial is frozen.

“Some things not to do would be to put it in the microwave. The best option if your test is frozen is just to leave it, set it out at room temperature and just let it thaw,” Reisch said.

You can make sure your test is working properly by checking the test sticks that come in the pack.

“In the window with the control you’ll want to make sure you see a blue line next to that C and that’s how you’ll know your test is working properly,” Reisch said.

You can find more information on tests here.