Horses living under extreme hot temperatures

Hi! I just want to share this situation.  Two days ago, at Yuma, AZ.  I observed a baby horse living under extreme wheater conditions.  I call the Human Society looking for help or an advise, but they told me that there is no law that enforces people to build a roof for horses to protect them of the sun. So, I do not know how much time this species can survive under these cruelty conditions. Could somebody tell me what one can do in this case?

Thanks.