How to use the online timer
Ten minutes away from a desk is enough to be a break rather than a pause, and short enough that it does not turn into half an hour. The trick is deciding the end before the start, since the difference between a break and a drift is entirely whether anybody knew when it was supposed to finish.
Stand up and go somewhere else, even if that is only the far end of the floor. Looking at something further away than a screen does more than the walk itself, and in an air-conditioned office the change of position is most of the benefit. The count runs in this tab, so leave the page open on the desk rather than taking the countdown with you on a phone that will find something else to do.
Ten minutes outside is a seasonal proposition here: from November to March it is the obvious answer and in July it is not one at all. A stairwell, a quiet corner or a walk to a different floor works year round. Coming back at a decided moment rather than a felt one is what keeps a break from becoming the rest of the afternoon.
Common questions
Does ten minutes really help?
It does if you actually leave the desk. Standing up, moving, and looking at something further away than a screen does more than the length of the break itself in an air-conditioned office.
Should I take it outside?
From November to March, yes. In the hottest months a stairwell, a quiet corner or a different floor works better, and the change of position is most of the benefit either way.