[Retric]

This depends on how insulated they are. You could make gloves that allowed you to stick your hand in -200C all day long. It's the same reason winter coats work, slow heat loss below the body's heat protection and you get unlimited duration.

The problem is most gloves are designed for vastly warmer temperatures and you don't notice frostbite if your hand cools down slowly.

[semi-extrinsic]

> You could make gloves that allow you to put your hands in -200C all day long

I don't think so. The only way you could make an object like a glove for continuous LN2 exposure, and not have it be 2 feet thick, is multilayer vacuum insulation (like LN2 dewars use). But that would not let you move your hands or fingers at all.

[Retric]

Check out polyimide aerogels, it's flexible and has ridiculous insulating properties. On top of that your hands are providing heat which makes a big difference.

Though I suspect mittens are probably far easier to manufacture as that's what current designs for -60c use. Either way you are not going to have much flexibility, but could grab something.