There's no such a word as heaty in the dictionary which has been made to mean 身体热气 to the Chinese. Oh perhaps not until the western medicine fully appreciates the hot chi in our body.
On the other hand, I found out what the meaning of heath. And no wonder he (Heath) was cast for BBM - heath means an area of open wild land covered with rough grass and low plants.
Unfortunately this silly connection can't be strengthened by bringing in his last name. Ledger just means the book where entries regarding your account is recorded.