A two-year-old girl has died of heatstroke in north-west Spain after being accidentally left in her father’s car during an unseasonably hot spell that could push temperatures in some areas to 38C (100F).

The child, who has not been named, went into cardiac arrest on Wednesday afternoon after spending several hours inside the vehicle in the Galician town of Brión after her father forgot to take her to nursery.

According to media reports, the man had driven his older child to school that morning and had intended to drop the toddler at nursery when he was distracted by a phone call. Instead of heading to the nursery, he went to work, leaving the child in the car.

The alarm was raised that afternoon when the girl’s mother went to pick her up from the nursery at 3pm and was told she had not been dropped off that morning. Realising what had happened, the parents called the emergency services and the girl was taken to a health centre in the nearby town of Bertamiráns, where she was pronounced dead.

Police are investigating the incident and the family is receiving psychological support.

Brión town council declared two days of official mourning for the girl and said a minute’s silence would be held in her memory on Friday.

“We would like to offer our deepest condolences and all our support to the family of the little girl who lost her life in Brión yesterday, as well as to all her friends, while we make all the municipal resources they need available to them in these difficult times,” the council said. “May she rest in peace.”

Spain has been bracing for the kind of heat more commonly associated with midsummer. The state meteorological office, Aemet, said the “exceptionally high temperatures” could reach 36-38C in some southern parts of the country.

“Throughout May, we have recorded a prolonged period of below-normal temperatures,” it said. “Now comes the complete opposite: a period of very high temperatures for this time of year across most of the country. In fact, some days could break heat records.”

Aemet said the hot spell, which does not meet the technical criteria to be declared a heatwave, would probably last until the middle of next week.

Spain, one of the European countries most exposed to the effects of the climate emergency, has experienced a growing number of heatwaves and a sharp increase in large forest fires in recent years.

A 2022 Aemet study found that the arrival of 30C temperatures across Spain and the Balearic islands had come, on average, 20-40 days earlier over the previous 71 years.

“The summer is eating up the spring,” Rubén del Campo, an Aemet spokesperson, told El País at the time. “What’s happening fits perfectly with a situation where you have a warmer planet,” he said, adding that rising temperatures were a “direct and palpable [consequence] of climate change … The climate in Spain isn’t the one we used to know. It’s got more extreme.”

Spain recorded its highest ever temperature in August 2021, when the mercury in the Andalucían town of La Rambla, near Córdoba, reached 47.6C.