I cannot speak for the entire United States I can only speak for us Virginians, we had a crazy winter and now it's being followed by a crazy summer.
The Horse had a great article for those of us who must press onwards and show or deal with this heat.
Summer Riding: When the Rider is Hot the Horse is Hotter
To stock up on electrolytes visit a ApSHA sponsor: Valley Vet. Portion of your money goes towards our year end series.
As a member your account should already be flagged, but you can send them a quick email to make sure your money will benefit the ApSHA.