All linemen, especially those who deal with live electrical apparatus, use personal protective equipment (PPE) as protection against inadvertant contact. This includes rubber gloves, rubber sleeves, bucket liners, protective blankets, etc.
All live line work PPE must be kept clean from contaminents and regularly tested for di-electric integrity. This is done by the use of high voltage electrical testing equipment [examples can be found here: http://www.hanco.com/HancoTestingEquipment.html].
Other general items of PPE such as helmets are usually replaced at regular intervals.