At first I thought it was a typo, but inserting the character 煜 into birthday wishes or the like seems to be common, e.g.
I have several problems:
What does it mean?
WWWJDIC has "bright, shining, brilliant", which sort of fits.
How is it pronounced (if at all)?
The readings given in WWWJDIC are イク, オウ, かがや・く, although none of them look like a particularly meaningful interjection.
How is it typed?
None of the readings イク, オウ, かがや・く, produce the character in my IME (although I do get 燠, which has the readings イク, オウ, おき and あたたか・い).