It can be hard to stop when you are tired, especially when you are engaged in a task.
Most people become so focussed on what they are doing they don’t realise how tired they are.
But continuing whilst tired leads to an increase in the probability that the quality of your work will diminish and can be dangerous.
V-CAF, an Apple Watch app, informs you when your tiredness levels increase and is ideal for helping you stay alert and focused.