Rapid Tests and Cold Weather

Many people have recently filled out online forms to receive free COVID antigen tests from the federal government or Vermont by mail. (If you would like tests and have not yet registered for them, see this article for details about how to order.) Receiving tests in the mail has prompted many people to ask, “will extreme cold temperatures ruin tests?” Here’s my advice.

• A few hours of very cold temperatures will not likely harm the tests. Nonetheless, check the mail often and bring test kit packages inside as soon as possible.
• Read package, and let the tests come naturally up to a temperature within the “store at” range marked in the instructions.
• Definitely let the tests reach a temperature within the “store at” range before using them.
• Follow testing instructions carefully.
• Each test includes a “Control Line,” sometimes marked with a letter C. The control line appears on every successful test, regardless of the results. It provides reassurance that you completed the test correctly. If the control line does not appear within the time indicated in the instructions, there may be a problem with the test or how you administered it. Carefully administer a second test to ensure your results are accurate.

Karen Bond is the director of Laboratory Services at Southwestern Vermont Medical Center, part of Southwestern Vermont Health Care, in Bennington.