A hi vis work shirt is one of the most critical hi vis clothing.
Hi vis long sleeve work shirt, can help you to be seen in the building site, driving, or walking across the road.
If wearing a high visibility shirt increases the chance of getting seen by others. 
The important thing about the work shirt is that it has reflective tape, when the light reflects, then people will see those who are working or walking in the condition,
The loose design and thickness help to work easier in the Summer.