use of reverse cycle air cons ( heat pump) in high ambient temp

[Quicksave]

Hi,
I am looking for some advise / opinion on the use of reverse cycle aircons for the brooding of day old chicks.
The ideal brooding temp for the first week is approx 30 Cel.
I've seen that most simple domestic heat pumps will heat up to about 31 Cel and therefore should work.
However, I have some concern on how effective the ' heating mode' is when external ambient temps reach 26-28 Cel
Plse advise
Thks