Autistic 2 year old safety in cot ?

My special little boy climbs absolutely everything and loves the sensation of teetering on the edge of sofas, chairs etc ....he usually safely slides off them and gives me a mischievous grin, my problem is he has started to climb out of his cot in the early hours and the fall is higher, does anybody have any advice how to make a cot higher or suggest something to help prevent this ( he is sensitive to loud noises or telling off ) ...Thank you