A needle guard for protecting a user from a needle pulled from a front end of the needle guard to a rear end of the needle guard, the needle guard comprising: an upper jaw that includes a roof , two opposed upper side walls extending down from the roof, each upper side wall including an upper edge depending from the roof , a curved side edge at the front end, and a substantially straight bottom edge abutting a bridge slot at a rear end of the bottom edge , the upper jaw abutting a hinge ; the hinge abutting the upper jaw and a lower jaw , the hinge including an upper hinge edge and a lower hinge edge defining a rear slot , wherein the bridge slot projects beyond a point where an extension of the bottom edge and an extension of the upper hinge edge would intersect; and the lower jaw abutting the hinge and including a floor , two opposed lower side walls extending up from the floor toward the upper jaw , each lower side wall including a bottom edge depending from the floor, a top edge facing the bottom edge of the upper side wall and extending toward the front end to meet the bottom edge of the lower side wall, said top edge of the lower side wall and said bottom edge of the upper side wall defining a front slot , and a latch extending from the lower side wall opposite said bridge slot , wherein the front slot defines a cavity opening at the front end of the needle guard , the front slot connects to the rear slot , the latch has a tip portion that together with the bridge slot defines an S-shaped path through which a winged needle passes from the front slot to the rear slot and the tip portion blocks the winged needle from pulling out of the rear slot along the S-shaped path. an upper jaw that includes a roof , two opposed upper side walls extending down from the roof, each upper side wall including an upper edge depending from the roof , a curved side edge at the front end, and a substantially straight bottom edge abutting a bridge slot at a rear end of the bottom edge , the upper jaw abutting a hinge ; the hinge abutting the upper jaw and a lower jaw , the hinge including an upper hinge edge and a lower hinge edge defining a rear slot , wherein the bridge slot projects beyond a point where an extension of the bottom edge and an extension of the upper hinge edge would intersect; and the lower jaw abutting the hinge and including a floor , two opposed lower side walls extending up from the floor toward the upper jaw , each lower side wall including a bottom edge depending from the floor, a top edge facing the bottom edge of the upper side wall and extending toward the front end to meet the bottom edge of the lower side wall, said top edge of the lower side wall and said bottom edge of the upper side wall defining a front slot , and a latch extending from the lower side wall opposite said bridge slot , wherein the front slot defines a cavity opening at the front end of the needle guard , the front slot connects to the rear slot , the latch has a tip portion that together with the bridge slot defines an S-shaped path through which a winged needle passes from the front slot to the rear slot and the tip portion blocks the winged needle from pulling out of the rear slot along the S-shaped path. <EOS>