Final answer:
Children have a higher risk of decreased thermoregulation compared to adults during exercise, making them more susceptible to heat-related illnesses.
Step-by-step explanation:
The primary risk for children compared to adults during exercise is decreased thermoregulation. Children have a harder time regulating their body temperature during physical activity, which puts them at a greater risk of heat-related illnesses. This is because children have a larger surface area to body mass ratio, which leads to increased heat loss and decreased thermoregulation.
An example of this is when children participate in vigorous exercise in hot weather without adequate hydration and rest, they are more susceptible to heat stroke or heat exhaustion.