There's nothing like a quick power nap to re-energize yourself, make you more alert, and feel much more positive about whatever tasks the rest of the day has in store for you.
On the other hand, we've also all experienced those mid-day naps which can leave us groggy, disoriented, and in no mood to deal with the day, let alone its many tasks.
If you nap any longer than this, you run the risk of falling into a deeper sleep, one that waking up in the middle could leave you feeling groggy and/or grumpy.