When to stop? When your living (listening) room becomes too hot to handle. My living room is now reaching 26°C from late afternoon onwards and it's about as much as I can take. I've got a Meaco fan which does a decent job of keeping my body temperature within limits at its lowest setting. But once it starts hitting 27°C, well that's where I draw the line. The fan is intrusively loud at the next highest setting so there's only one thing for it: I need to move into my bedroom, for 6 weeks or so, and fire up System B.
Not even Addis pads can help me here!