Crack the lid and it’s fine

Crack the lid and it’s fine.

Yes, you can microwave a glass lunch box straight from the fridge, but not with the lid sealed shut. Leave it cracked so steam can escape.

The glass itself is usually the easy part. If it’s labeled microwave-safe, cold-to-hot shock isn’t a big deal. Freezer-to-microwave is riskier, but fridge-to-microwave is okay for tempered glass. If it’s old, unmarked, or has metal trim, don’t chance it.

The lid is what gets people. Most lids are plastic, and if the lid doesn’t say microwave-safe, it can warp or leach regardless of venting. If the lid is safe, just set it on top with one corner open, or use its built-in steam vent. If it’s still airtight, pressure builds and you’ll get a pop-off lid and a mess.

If your lid isn’t microwave-safe, cover the dish with a microwave-safe plate or a damp paper towel instead. And heat in short bursts, stirring halfway — that prevents hot spots better than blasting it on high.

Your lunch won’t explode if you let it breathe.