Abstract: A jersey having a back and an openable front. An enclosure is connected to the back for removable insertion of a liquid-fillable bladder within the enclosure. A shoulder harness is connected between upper and lower portions of the enclosure for shoulder support of the liquid-fillable bladder when the jersey is worn with the liquid-fillable bladder inserted within the enclosure. The shoulder harness has left and right upper straps which are respectively connected to the left and right sides of the upper enclosure portion; and, left and right lower straps which are respectively connected to left and right sides of the lower enclosure portion. A left strap coupler adjustably couples the left upper strap to the left lower strap; and, a right strap coupler adjustably couples the right upper strap to the right lower strap. The shoulder harness is also provided with bladder supports.