Which of the following is true regarding the heating effects of the sun?

The assertion that overexertion is a more likely cause of heat stress than the heating effects of the sun is valid in certain contexts. While the sun undeniably contributes to heat accumulation, particularly when horses are exposed for extended periods, the degree of heat stress experienced by a horse can also significantly depend on exercise intensity and duration. Overexertion involves both physical exertion and environmental heat, which can exacerbate the risk of heat stress.

In situations where horses are being worked hard — for example, during training sessions on hot days — their bodies generate heat through muscle activity, which can lead to overheating more swiftly than sun exposure alone might cause. Therefore, it is crucial for caretakers to monitor not just the weather conditions, but also the workload and hydration levels of the horse to prevent heat stress effectively. The complexity of factors that contribute to heat stress in horses emphasizes the need to consider both environmental and physical exertion elements.

This reasoning also highlights why sun exposure alone, while important, does not fully explain heat stress scenarios, nor does it account for the individual variability of horses. Factors such as age, fitness level, coat thickness, and acclimatization play roles in how heat stress manifests across different horses, indicating that not all horses are equally affected