Here are some ideas to keep your dog cool during the hot days of summer:
Keep plenty of fresh water out for them. Keep them hydrated.
Take regular breaks to cool down if you are outside with them.
Use an elevated or cooling bed if your house is a bit warm for them.
Give frozen treats and toys for them to play with.
Provide plenty of shade for them when they are outside.
Go swimming in any type of water hole with them.
Do your exercises at a cooler times of the day.