Cold weather and adhesive performance

Cold weather is hard on medical gear in ways people don't always expect. Adhesive gets stiff, batteries drain faster, meters may refuse to work, and insulin can freeze. This guide covers what changes below freezing and how to keep everything working.

Adhesive in the cold

Most medical adhesives grip best on warm, dry skin. Applied in the cold, they don't bond as well, and they may peel at the edges. Apply new sensors, sets and patches indoors at room temperature, then give them time to set before heading out. Dry winter skin can also flake under adhesive, so moisturize other areas but keep lotion off the site itself.

Layers rubbing against a device are another cold-weather problem. Thick jackets, ski pants and base layers pull at sensor edges. An overpatch helps, and so does placing devices where layers don't bunch.

Batteries and phones

Cold drains batteries quickly, and phones may shut down without warning in freezing weather. If you use your phone to see your CGM, keep it in an inside pocket close to your body. Carry a small power bank and keep spare batteries for any device that uses them warm too.

Meters and test strips

Meters and test strips have operating temperature ranges listed in their user guides. Below that range, they may show an error or an unreliable result. Keep them in an inside pocket. Cold fingers can also make it hard to get a blood sample, so warm your hands first.

Insulin

Insulin should never freeze. On cold days, carry pens and vials in an inside pocket or an insulated pouch close to your body, not in an outside backpack pocket or a car. Insulin that has frozen shouldn't be used, even after it thaws. Pump tubing exposed to the cold should be kept under clothing.

Signs that can be harder to notice

Shivering and cold, numb hands can feel similar to some symptoms of a low. If you're not sure, check. Keep low treatments where you can reach them with gloves on, such as a chest pocket.