Pain in the neck, shoulders, and back after exposure to sunlight may be due to muscle strain, heat-related fatigue, or mild sunburn. Initial relief can come from resting, staying hydrated, using cool compresses, and gentle stretching if comfortable. Over-the-counter pain relievers such as paracetamol or non-steroidal anti-inflammatory drugs (NSAIDs) may help reduce pain and inflammation, but these should be used as directed and with caution if you have any medical conditions. If the pain is severe, persists for several days, and is associated with swelling, redness, numbness, or weakness, it is essential to consult a doctor for proper evaluation and targeted treatment.