Temperature sensor  in your case, is located in the shelf,  and  are in ESH modules.
I would ignore those messages, because 2 and 3 are working properly.
If the air condition in a server room would go off and temperature up, I belive some other sensors; chassis, other shelfs, or these  and  would notice that as well.
To do a power cycle for the shelf would need a maintenance break (Best practise, halt the filer first, and then shelfs).
I wouldn't do that for just power cycling, I would try to get a replacement shelf from netapp, and replace it during maintenace break.
Not only do the note, that power cycle didn't help, let's find out when we can do this again, and lets then replace the shelf.
It's innoing to get those errors to the log, but it doesen't look serious because you still have plenty of sensors to check the temperature.
When doing a power cycle on the shelf is there any impact on volumes that utilize disks on the shelf? Since it's not an issue to production at the moment and more of an annoyance an outage won't be approved to power cycle for just fixing a sensor -- which the temperature is roughly the same as below.
It is not supported to remove shelf when filer is running (by netapp) In this case I think it is same as power cycling it. Filer can panic etc.