Columbia Blue | DiamondCool™ Performance Unisex Fit Short Sleeve T-Shirt

The Ultimate Heat-Defeating Short Sleeve Training Tee

Don't let blistering summer days cut your workout or workday short. The DiamondCool Men’s Cooling Short Sleeve Performance Shirt is engineered to turn down the heat when your environment cranks it up. Built for runners, construction crews, and outdoor adventurers, it delivers elite athletic style with unmatched thermal relief.

Patented Moisture-Activated Cooling

This shirt doesn't just block sweat—it uses it against the heat. Our patented cooling fabric triggers a thermal drop the second it comes into contact with moisture. Whether activated by intense sweat or a quick splash of water, the fabric drops as low as an icy 58°F (14°C), providing a continuous cooling sensation across your core.

Certified UPF 50+ Sun Shield

Take your outdoor training to the next level without worrying about UV damage. Rated at UPF 50+, this performance tee blocks 98% of harmful UVA and UVB rays. It offers premium, lightweight coverage for your chest, back, and shoulders during peak solar hours.

American Made & Eco-Friendly

• Repreve® Recycled Fibers: Every shirt is sustainably crafted from recycled plastic bottles, pulling waste out of ecosystems and turning it into ultra-durable, buttery-soft performance gear.

• Made in the USA: Proudly cut and sewn domestically from premium imported materials, ensuring zero compromise on quality, fit, or ethical manufacturing standards.

Technical Features & Specs

• Instant Thermal Drop: Fabric cools as low as 58°F when damp.

• Maximum Solar Defense: Certified permanent UPF 50+ protection.

• Sustainable Performance: 88% eco-friendly Repreve fabric.

• 4-Way Stretch: Zero-friction design tailored for unrestricted movement.

• Anti-Odor Shield: Advanced antimicrobial properties keep you fresh post-workout.

• Craftsmanship: Made in the USA of imported fabric.