Here is my (Scott) translation of this alert from the Ministry of Public Health. Note that the scale below the house says that no protection is needed at levels 1 or 2, protection is needed at levels 3 through 7, and extra protection or no exposure is recommended at levels 8 through 11:
The current atmospheric conditions of low relative humidity (few clouds) in Quito and in various provinces of the Sierra (high Andes) have resulted in readings of EXTREMELY HIGH ultraviolet radiation. This situation is caused by episodes of photochemical smog, resulting in the ozone being at the lowest level of the atmosphere.
For today, Thursday the 21st of September, it is predicted in the city of Quito that the index of ultraviolet radiation (UV) will vary between 11 and 14, levels that are considered to be in the category Extremely High.
The Ministry of Public Health recommends that citizens in the entire Sierra region receive ZERO EXPOSURE. Contrariwise, use sun protection, cover your head (hats or umbrellas), clothes that cover the whole body (not shirts with uncovered necks), preferably not black. For your health, take precautions, especially if you have sensitive skin.