He has complained several times a day for the last week or so, although notably not while he's been busy having fun!
He says his arms feel weak and his hands won't stop shaking. It is certainly true that his hands are shaking, to the extent you can clearly see it, especially if he's holding something e.g cutlery, pen
But, it isn't all the time, seems to me it's only when he's thinking about it, but I suppose it could be the other way round, i.e. he thinks about it when it's happening.
Cause for concern or will blow over?