Mexico is fighting 159 active wildfires across the country amid the current heat wave that has also put stress on the nation’s power grid.

Mexico’s national weather service issued a warning that at least 12 states would experience temperatures higher than 45°C (113°F), with large swathes of the rest of the country expected to see temperatures higher than 30°C.

The heat wave has increased demand for power, prompting the country’s grid operator to declare the system in a state of emergency on Thursday evening for the second time this week. This means available power was below adequate levels. On Wednesday, operator Cenace also declared the system in a state of alert.

Mexico’s national forest commission (Conafor) said the wildfires have spread across 75,474 hectares (186,500 acres). It also said that 30 of the fires were in protected natural areas.

Mexico City and several other regions in the country have faced blackouts, Milenio reported Thursday. Some schools shut down due to high temperatures in areas such as San Luis Potosi, El Universal reported.

Parts of the country have also been dealing with drought. The capital’s surrounding metropolis of about 20 million people has seen intermittent water supply in recent months due to lower rainfall than expected.