Which characteristic is NOT recommended for work shirts used when pole climbing?

When selecting work shirts for pole climbing, proper material and design are crucial for safety and functionality. Option D, synthetic materials, is identified as the characteristic that is not recommended because these materials can be more prone to melting or catching fire if exposed to electrical hazards, which are significant risks in pole climbing and utility work. In contrast, long sleeves, 100% cotton, and sleeves buttoned and extended provide additional protection, helping to shield the skin from abrasions, environmental elements, and potential electrical hazards. Cotton is particularly favored due to its breathable nature and its flame-resistant properties compared to many synthetic fabrics, making it a safer choice in high-risk environments.