ROME — The Uffizi Galleries art museum in the Italian city of Florence shut its doors to the public Friday amid a heat wave because of problems with its air conditioning system.

The Renaissance art capital has a reputation for being one of Italy’s hottest cities every summer. But a heat wave gripping the nation for days, and coming on top of a weeks-long drought, was making it tougher to stay cool.

Temperatures in Florence hit at least 101 F (nearly 39 C) on Friday. Rome temperatures this week were around 100 F (38 C).

Uffizi Galleries director Eike Schmidt said because the level of the Arno River, which flows through Florence, was so low the museum couldn’t draw as much water from it as it usually does for its industrial-scaled cooling system.

Standing outside the galleries as tourists waited in line for ticket reimbursements, Schmidt told SkyTG24 TV the cooling system was still working well enough to keep its masterpieces climate-controlled and avoid damage.

But the heat generated by “even a few hundred people” visiting the museum could tax the system to the point it wouldn’t be able to guarantee the cool temperatures needed to safeguard the paintings, he said.

The Uffizi had arranged for trucks to bring in enough water to make sure the Uffizi’s air conditioning would be up and running on Saturday for the public to return, he said.

Initially, the museum said it had hoped to re-open its doors later Friday afternoon.