Further to Gargoyle:
So I looked it up on google:-
"heads up -- As in "Giving you a heads-up" - Forewarning someone (usually a superior) of an impending event, where they would otherwise suffer negative consequences, had it not been for your selfless vigilance and concern for their well-being."

'Twould appear to be a compliment.

Ta

My partner often reminds me I am safe 'cos she has got the cushion ready for when I fall off my high horse, but sometimes things just have to be said.

Andy