Parisians will be temporarily barred on Friday from buying and drinking alcohol in public, as the city authorities try to limit the strain on France’s health system amid record-breaking heat.

The Paris police chief, Patrice Faure, has barred alcohol consumption in streets and parks from midday on Friday and the sale of alcohol from 6 p.m. It was not immediately clear how long the restrictions, which were also briefly enacted but not widely respected during a music festival this past weekend, would remain in place.

Separately, Mr. Faure also suspended sports competitions and asked the organizers of other public events, including a music festival and a Pride march, to postpone their gatherings. If they do not, his office said in a statement, he may order their postponement anyway.

Mr. Faure told journalists on Thursday night that the outdoor drinking ban was because “alcohol in direct sunlight has devastating effects that result in our firefighters and emergency medical services being tied up and called upon at a time when other people might need their assistance.”

Though Paris’s hospitals are not showing any signs of congestion, Mr. Faure said, “My job is to ensure that the emergency response and hospital care systems are not overwhelmed.”

Any congestion would be “disastrous,” he said, “since it could lead to additional accidents or even deaths due to an inability to provide care.” During the earlier restrictions over the weekend, he had said that no one would be detained for ignoring the ban but could face a fine.

France’s health minister, Stéphanie Rist, warned on Thursday that over the past 24 hours, Paris had recorded four times the normal rate of people suffering cardiac arrest.

Ms. Rist said it was too early to estimate the excess mortality rate caused by the heat wave. But the government estimated that 40 people had drowned in heat-related accidents between June 18 and June 23, and according to prosecutors at least three children have died after being trapped in cars.

A 3-year-old boy was found dead in his family’s car in a Paris suburb on Wednesday, and in the southern city of Carpentras two siblings aged 2 and 4 died after they were found unresponsive in their parents’ car on Monday.

Prime Minister Sébastien Lecornu said on Thursday that he had activated the highest level of mobilization within the health care system, bolstering hospital staffing and prioritizing care for people afflicted by the heat. The health ministry later announced a special fund of 100 million euros — or roughly $114 million — to allow hospital services to buy air-conditioning units and fans.