A debate has been sparked after Spain's government moved to prevent offices, shops and other venues from setting air conditioning below 27°C in the summer.
The decree, published on Tuesday morning, will also stop heating from being raised above 19°C during the winter.
The rules will be mandatory in all public and commercial buildings, including bars, cinemas, theatres, airports and train stations.
It is extended as a recommendation to Spanish households.
The government passed the bill as part of a bid to reduce the country's gas consumption by 7% in line with the recent European Union energy agreements to limit dependency on Russian gas.
Teresa Ribera, Spain's ecological transition minister, said the measures -- which include switching off store window lights after 10 pm but not street lighting -- would initially be maintained until November 2023.
She encouraged Spaniards to join the cuts, saying it would not only reduce consumption levels but also bring down households' energy bills.