These steps assume you have created an electronics cooling study in the Simulation workspace.
On the Setp toolbar, in the Thresholds panel, click Temperature Thresholds to open the Temperature Thresholds dialog.
In the canvas, select a component that has a maximum temperature threshold and confirm that it appears highlighted in blue in the canvas.
In the Temperature Thresholds dialog, in the Maximum Temperature column, click on the highlighted row to activate edit mode.
Type the maximum temperature that the component can reach, then press Enter on your keyboard.
Continue to select components from the canvas, and enter their Maximum Temperature in the Temperature Thresholds dialog, until all the components of interest have a Maximum Temperature value assigned.
When you have finished, in the Temperature Thresholds dialog, click OK to accept the changes and close the dialog.