A sleeve for a garment, comprising: a front panel attached to a back panel along respective first and second side edges thereof, the back panel having upper and lower vents formed proximate an elbow portion thereof; and, upper and lower flaps formed on the back panel above and overlapping the upper and lower vents, respectively; wherein the upper and lower flaps are moveable between a closed position when the sleeve is straight through the elbow portion and an opened position when the sleeve is bent at the elbow portion to thereby allow increased airflow through the upper and lower vents when the garment is in use.