Are you asking how to update the temperature case for a particular section?
If so, just highlight the area you are wanting to change, then go to
Insert > Operating Pressure & Temperature
This will allow you to modify the conditions for each of the load cases that you defined in the model setup.
This can be done on as many sections as you want.
You define how many cases you want in the project setup and can be changed at any time under
Tools > Model Options > General