If you are going to smoke in your office, make sure a colleague hasn't stubbed their cigarette out in your can of Coke before you drink from it.
On Friday, The Daily Telegraph unearthed an old STV programme that documented Gordon Brown's first days in the Treasury after the 1997 election.
The behind-the-scenes cameras are given a rare look at how Brown's advisers: Ed Balls, Ed Miliband and Charlie Whelan operate.
In one segment of the programme, Balls, then the economic adviser to Brown, is seen chatting to Financial Times journalist Robert Chote on the phone in his office while smoking. Stood next to him also smoking a cigarette, is Whelan. As Balls speaks to Chote, who now heads the Office for Budget Responsibility, Whelan can be seen dropping his cigarette into a can of Diet Coke on Balls' desk.
A few seconds later, as the pair watch how the BBC News covers the Treasury's announcement that the Bank of England was to be stripped of regulatory powers, Balls takes a few swigs from the Coke can. Which must have tasted nice.
For the sake of Balls' health, we hope the sequence of events was distorted due to the editing of the programme.