What To Do
Assess the horse's general health using the Whole Horse Exam (WHE), paying particular attention to their attitude and appetite, and look for other signs of illness.
If your horse has a mild fever or you believe that it may be transient (related to exercise or trailering in hot weather), you can monitor the horse and reassess their temperature in an hour.
However, if the fever persists or your horse is showing other signs of illness, you should immediately contact your vet to discuss your findings and concerns.