Can heat cause to act horse lethargic?

Yes, heat can cause a horse to act lethargic. High temperatures can lead to heat stress or exhaustion, which may result in decreased energy levels, reduced appetite, and overall sluggishness. Additionally, dehydration and electrolyte imbalances due to excessive sweating can further contribute to a horse's lethargy in hot weather. It's important to monitor horses in high heat and provide them with adequate water, shade, and rest.