I let the child try to climb the barbed wire fence
Are you trying to get them seriously injured?
It's very unlikely to hurt the child.
You don't think the child will get hurt on barbed wire but that seems to be unthinkable to me. Its okay to let them have fun but barbed wire is very sharp, it can stick the child in his skin and injure him. The ambulance will come and take him away because you let him climb the fence.
Not really. I think it'll be fine.
The barbed wire is so sharp. One wrong move could seriously injure them. You should try to keep them away from the fence so that they do not get hurt.