My first Half IM -Forecast 41 degrees C (105F) ! What do i do?

hey everyone, thanks for the advice. frozen drinks, fozen hat- good ideas. I will be wearing a tri suit and can carry a frozen towellet.
and ice in the cap.
I expect the run to be a disaster, so i will back it off on the bike. It may also be quite smokey, as we have had some bushfires (wildfires) in that part of the state (NE Victoria- Australia)
I am pretty determined to finish, as this is my first crack at this distance and i have a few mates doing it, so it may be a smackdown. But i would rather race smart and finish than go all out and die trying.