Dic: Synonyms: aware, cognizant, conscious, sensible, awake, alert, watchful, vigilant

These adjectives mean mindful or heedful:

• Aware implies knowledge gained through one's own perceptions or by means of information:
  .. Are you aware of your opponent's hostility?
  .. I am aware that the legislation passed.
• Cognizant is a formal equivalent of aware:
  .. "Our research indicates that the nation's youth are cognizant of the law" (Jerry D. Jennings). 
• Conscious emphasizes the recognition of something sensed or felt:
  ... "an importance . . . of which even Americans are barely conscious" (William Stanley Jevons). 
• Sensible implies knowledge gained through intuition or intellectual perception:
  .. "I am sensible that the mention of such a circumstance may appear trifling" (Henry Hallam).
• To be awake is to have full consciousness of something:
  .. "as much awake to the novelty of attention in that quarter as Elizabeth herself" (Jane Austen). 
• Alert stresses quickness to recognize and respond:
  .. I remained alert to career opportunities. 
• Watchful and vigilant imply looking out for what is dangerous or potentially so:
  .. The watchful parents protected their toddler.
  .. The ranger kept a vigilant eye out for forest fires.

... The American Heritage