Weigh each of the team in the gear they are about to play in. Record the weight of each player. Play the full game and hydrate as you would normally. Record the difference. Here are some guidelines to follow.
Any fluid loss is a potential problem.
The players mental alertness will begin to deteriorate. There will also be lower energy levels and a dry mouth. At this level there can be a severe drop in mental alertness. Low energy levels and very dry mouth will be evident. This is the level where IV fluids are used to hydrate athletes and children.