In low-light or low-visibility situations, hi-vis (high visibility) workplace shirts are shirts that make the wearer highly apparent to others. These shirts generally have reflective tape or striping and fluorescent colours, like vivid yellow or orange, to increase the wearer's visibility. They are frequently worn by employees in professions that require people to be able to see them clearly in order to ensure their safety, such as emergency services, transportation, or construction. The shirts often meet requirements for high-visibility clothing defined by groups like the International Safety Equipment Association (ISEA) or the American National Standards Institute (ANSI). They are often constructed from strong, breathable materials like polyester or cotton blends, and they could include conveniences like pockets or a button-front design.