Most of the areas affected are in the south of the country, where temperatures regularly drop below freezing in the Southern Hemisphere winter, BBC News reported Saturday.
The state of emergency was declared in 16 of Peru's 24 regions as temperatures dropped to as low as minus 13 degrees Fahrenheit.
Hundreds of people -- almost half very young children -- have died of cold-related diseases such as pneumonia in Peru's mountainous south, the BBC said.
Poor rural populations living at almost 10,000 feet above sea level are the most affected, officials say.
Health officials say malnutrition, extreme poverty and poor living conditions are major contributing factors to seasonal winter deaths.