Some European mountain hut associations now require all liners used in their huts to be microwaved at 600W for at least one minute to help control bed bugs.
We've had questions from adventurers about whether this could damage their liner, so our team put every liner in our range through a microwave test.
Does my liner need to be dry?
Yes, and this matters more than you might expect. Microwaves heat moisture, so a damp liner can get hot enough to be damaged. That includes a liner that isn't visibly wet but has picked up moisture from humid air, a damp pack, or a night in a cool hut. Before microwaving, make sure your liner is thoroughly dry all the way through, including seams and any thicker sections. If it's been packed away damp or stored somewhere humid, give it time to air out first.
Which liners should not be microwaved?
All 2026 Sea to Summit liners should stay out of the microwave. Their barrel locks contain a metal spring, which can spark in a microwave and melt the barrel lock and possibly the fabric around it.
Fleece and Fleece weight liners should also not be microwaved.
Their metal zipper slider can spark, which may melt the surrounding material.
How can I tell if my liner has a metal barrel lock?
If your liner's drawcord uses a spring-loaded barrel lock (the small toggle you squeeze to loosen the cord), it contains a metal spring and should not be microwaved. If you're unsure which version you have, treat it as not microwave-safe.