Atlas.......
Looks like a very nice boy, thanks for sharing his picture.
As for your question on heat tolerance - this is a bully breed with a short muzzle so their heat tolerance will be not be a great as other breeds. We live in the central valley of California where summer highs can reach 105+, the OEB does well outside in the heat (altho mine are sprawled out in the house on those days!!). If you plan on hiking on days when temps are 95 and above then a bully breed may not be what you are looking for.
Training... has been a little different! I bred, showed and hunted over Labs and Flatties for over twenty years, so the OEB has been quite an adjustment but I do love all the qualities this breed has.
Best of luck on your search.
Bev