Screw clamps. Screw clamps are types which use a screw mechanism to adjust the jaws and clamp a workpiece in place. The types which are found in the screw clamp category include G clamps (also known as C clamps), F clamps, edging clamps, wooden hand screw clamps and rack clamps.
Dry drowning usually happens soon after exiting the water, but with secondary drowning, there can be a delay of up to 24 hours before the person shows signs of distress. Both can cause trouble breathing and, in worst-case scenarios, death.
Dry Drowning and Secondary Drowning. If you're like most parents, you probably figure once your child is done swimming or playing in the water, his risk of drowning is over. But dry and secondary drowning can happen hours after he's toweled off and moved on to other things. There are steps you can take to keep your child safe.