One's physiological state is less than preferable on awakening.
AND the course of action taken to rectify this situation is to conduct the daily routine in a hooded sweatshirt with the hood of the aforementioned sweatshirt up over one's head.
causes for a hood up day may include: flu, swine flu, man flu, female "tummy aches", TVOD, GFDI (girlfriend disengagement illness), BFDI (boyfriend disengagement illness), embarassment, lazyness, depression, cock blocking, WBCFS (work backlog chronic fatigue syndrome), FPS withdrawal syndrome, being mauled by a bear, failing an exam, rape, car sickness, realisation of lack of funds, watching "marley and me", bad night's sleep, no night's sleep, post mid day nap dizziness, dehydration, hunger, bad hair day, failure (all forms) and rejection
However the most common cause of a hood up day is the consumption of copious ammounts of alcohol the previous night, resulting in a catostrophic hangover.
man 1: oh, hi steve i was wonderi...
man 2(interupts): HOOD UP DAY!
man 1: ok maybe later.
Example 2 (used in a phone convesation)
girl 2:oh, hiya jen
girl 1:seriously becca, you have to come over and make me feel better i'm having a massive hood up day
girl 2:i'm on it i've got the little mermaid on dvd, but you need to decide, cookie dough or phish food