design of skylight structure for double height hall

n an existing house,the hall size is 14ftx20ft and it has double height of 

20ft.The roof has an opening of 8ftx8ft which has been covered with aluminium structure and fibre sheet.

In summer,the temperature inside the hall is raised too much though light is there.We want to have light at the same time the hall should not get heated up in summer at the same time rain water should not enter the hall.

Pls. suggest suitable remedy.