The law forbade the Mahram to wear a complete sewn dress, such that every garment is sewn around the body or waist.
As regards covering of the body at Mina with a blanket or woven embroidery, there is nothing wrong in it, because the prohibition only applies to clothing on the body. Covering during sleep is not the same as clothing. This is because the cover sheet is not usually worn, and that is why it was narrated on the authority of the Prophet – may Allah bless him and grant him peace – that he said: “Do not wear T-shirts, turbans, or trousers…until the end of the hadith.”
The nature of clothes differs from the nature of a cover sheet. That is why nothing is wrong with the use of a cover sheet compared to sewn clothes or woven garments.