Following record temperatures in Germany this summer, a senior official in the Environment Ministry says the country needs a national heat action plan for next summer.

"I believe the lesson we have learned from this summer is: next summer we also need a national action plan that then bundles together everything from the [German federal] states," Environment Ministry State Secretary Jochen Flasbarth told public broadcaster ZDF on Sunday.

The federal government was working very closely with state governments, many of which already had heat action plans, he said.

Almost 10,000 people across Germany had died due to high temperatures by mid-July, according to estimates from the Robert Koch Institute (RKI), Germany's public health agency. That is more than in any full year since 2016.

Asked about the situation in hospitals, many of which are not equipped with air conditioning, Flasbarth sharply criticized the Federal Court of Auditors.

The Environment Ministry had a programme called Climate Adaptation in Social Facilities, he said, but the auditors had strongly criticized the ministry for significantly exceeding its powers.

Flasbarth said the government was determined to challenge the criticism.

"We want to tackle this, we even want to set a constitutional amendment in motion now so that this completely excessive criticism from the Federal Court of Auditors comes to nothing," he said.

Flasbarth stressed that adapting to extreme heat was a challenge for society as a whole and said progress was too slow.

He also criticized those who repeatedly argued for a more cautious approach to tackling climate change, saying they were "creating the suffering of the day after tomorrow."