The D3 operates 10 C hotter than the L3 on a normal day. They're going to be tough on a hot day. I've ordered a 12kBTU portable aircon from gmc. Should be arriving today.
I've also decided to move my portable aircon in to help on those super hot days. I suppose the added cost will be worth the peace of mind.
Also, the D3s can get shafted, I'm selling mine soon as it lands. lol.