What first aid step is essential when assisting a person affected by excessive sun exposure?

The first aid step that is essential when assisting a person affected by excessive sun exposure includes giving them cold water or fruit juice. This is crucial because excessive sun exposure can lead to dehydration, overheating, or heat exhaustion, and rehydrating the affected person is a top priority. Cold water helps to cool down the body temperature and replenishes lost fluids, which is important for recovery.

In the context of excessive sun exposure, providing fluids supports the body's ability to regulate temperature and can help alleviate some of the symptoms associated with overheating, such as nausea or dizziness. It is important to ensure that the person is conscious and can swallow fluids safely.

While other options may also play a role in first aid for sun exposure, they are not as directly critical as hydration at the onset of symptoms. For instance, wrapping in a wet cloth can provide some cooling relief but should not be the foremost priority if the individual is dehydrated. Similarly, applying sunscreen is important for sun protection but is not relevant in the immediate response to heat-related symptoms after exposure has already occurred. Getting someone indoors to rest is certainly beneficial for recovery, but it is more effective when combined with hydration.