In these temperatures, I take Blue on his long walk first thing in the morning when it's cooler. Then he burns off energy chasing his ball in the cool part of the house.
This morning, a boxer named Benny saw Blue, sat down and wouldn't move, kept watching Blue, lay down as he got nearer, then Blue went straight past ignoring him and Benny finally got up and continued his walk.
I got a sharer when I was struggling to find the time to look after my mare properly. She looks after mare 3 days a week. Doesn't pay anything, I was looking for a sharer to help with the workload not the finances.
What do you do with your horse? Do you need a school with jumps, a dressage arena, space to park a trailer or good hacking?
What part of the country are you looking in? Someone on here might be local to you and able to suggest somewhere.