I often use the JSON converter and simply set my message to msg.payload.temperature and I will be able to get the temperature data. However, now there is an error when I use the converter or the payload is undefined without the JSON converter. Please help!
Changing the string at the destination is a hack. Fixing the JSON at source is the better option.
PS, the string node is a waste of space, a function node and a one-liner (or even a change node) could easily have hacked up the string into valid JSON - i didn't mention it because it wasn't the "right thing to do"