This should be for no longer than necessary to effect the change of clothing and would only be appropriate where the change could be made quickly and easily.
Ni ddylai hyn gymryd mwy o amser nag sydd ei angen arnynt i newid eu dillad a dim ond lle y gellid gwneud hynny'n gyflym ac yn ddidrafferth y byddai hyn yn briodol.