High temperatures and high humidity create higher stress conditions for people and for horses. Horses require about one to two ounces of salt per day to provide help meet their requirement for sodium and chloride under normal temperature conditions, but this requirement can increase to four to six ounces of salt per day in very hot climates or under exercise conditions where sweat losses increase greatly.

Inadequate salt in the diet can result in abnormal eating behavior such as licking or chewing objects which have salt on them or licking/eating dirt. Water intake can also decrease, increasing the risk of impaction colic. In more extreme cases, horses will stop eating and could experience muscle incoordination.

A good option to maintain your horse's year around salt intake is to offer salt available free-choice, either in stalls or in a covered mineral feeder. Salt intake from loose salt has been observed to be higher than from salt blocks due to the ease of consumption; it can be challenge for a horse to lick enough salt off a salt block to consume the higher levels required during high heat and humidity.

It is absolutely essential that fresh water at an appropriate temperature be available at all times as well. Horses tend to consume less water if the water temperature is too high, even if they should be drinking more water in the warm, humid conditions