The most effective alternative is going to be avoiding the sun by keeping them inside and away from windows when the sun is at its peak. When sitting by windows, it can help to use blinds and curtains to keep any direct sunlight off their skin.The most effective alternative is going to be avoiding the sun by keeping them inside and away from windows when the sun is at its peak. When sitting by windows, it can help to use blinds and curtains to keep any direct sunlight off their skin.