diff --git a/README.md b/README.md
index 6de1b14..6fe41a7 100644
--- a/README.md
+++ b/README.md
@@ -22,3 +22,10 @@ to use the gui first
 ```
 > python app.py
 ```
+
+Inside, you will need to
+
+- select the environment
+- choose the temperature (5 degrees is fine?)
+- choose the pressure (720 to 780 mmHg)
+- and select the location on the map (right click and "set as observer location")