well there are some risks, i dont know them and couldnt list them all, but they couldget infections, if it is captive bred ad hasnt been outside before, depending ho big it is depends on if it could get lost. If it is a young snake then it might take fright and slither off before you can get hold of him/her. I would only think it is ok if you know the snake very well and even then keep a very close eye on it and dont lt it out for too long or too far away from you
If you have a cat or your neighbours do i would be very cautious. Kehhlyr said a while back about something in cat wee that is very bad for them. On the other hand, its boiling and would make some good photos.
I will be taking my royal outside if the weather stays good this week, but I will keep her on the table in the garden.