I want to set my climate to 0 when window opens and after closing set it back to it temp before. But to do that i need to save the temp anywhere. Can i write it into any field or something similar?
Use a slider 
I have one for morning/day/evening/night for each thermostat.
When I turn on “venting mode” all thermostats are set to their minimum and when turning it off, they are set back to the slider values.
Sebastian
The Idea with the slider is working great, but a sensor template would work also 