The Diamond HOTSPORT had the best result in the moisture wicking test and to quote Pete Reiser, author of the blog,
"I knew the Diamond was keeping me dry and cool and it is light-weight. It also feels similar to the Under Armour loose fit shirts I have been wearing for years. You want the best? The Diamond Hotsport is the best undershirt in this comparison."HOTSPORT shirts are available in 4 colors for $18.99 and up. They are rated for 75 degrees and up and also have Scentcheck® anti-microbial technology that neutralizes odor.
For the complete article, list of other shirts and comparisons, visit the Midwest Umpire Blog.
Umpire-Empire.com also had members have also given these shirts a 96% rating. Those reviews are available here.