Is it forbidden or reprehensible for a veiled woman to roll up her sleeves at work or elsewhere, and what is her punishment?

The primary purpose of hijab (definition) is concealment, and it is impermissible for a woman to expose any part of her body in front of non-mahram (definition) men, whether at work or elsewhere. As for her punishment in the afterlife, that is part of the unseen, known only through divine revelation. However, whoever displays any part of her body, even if only her forearms, may fall under the threat mentioned in the hadith (definition) narrated by Muslim from Abu Hurayrah (may Allah be pleased with him): "Two types of people from the inhabitants of Hell I have not seen: people with whips like the tails of cattle, with which they beat people, and women who are dressed yet naked, inclining [to evil] and inclined [to it], with their heads like the humps of camels, leaning to one side. They will not enter Paradise nor smell its fragrance, though its fragrance can be smelled from such and such a distance." They should be advised gently to cover their forearms, so that they may be a good example. And their being in this state is better than being completely unveiled.