The document provides instructions for coding an IoT thermostat that allows changing the target temperature from a web page by calling a cloud function. It instructs to 1) add a function to update the target temperature variable, 2) register this function as a cloud function, 3) add a form to the HTML to call this cloud function, and 4) test the functionality. A hint is provided to print temperatures to serial for debugging. The completed thermostat should display current/target temperatures, allow changing the target and mode, and indicate mode with an LED.