MONTREAL -- Quebec could run out of key medical supplies in three to seven days, Quebec Premier Francois Legault said Tuesday afternoon.

Legault said the shortage of medical supplies such as N95 masks, which are key in the fight by health-care workers against the spread of COVID-19, is the province's "top priority" at the moment.

Health Minister Danielle McCann said that supplies of masks are so low in Quebec right now that health-care workers have been asked to disinfect and re-use their masks as needed.

"Right now, we're using 10 times more medical equipment than normal," she said. "So what we used in one year, we're using in four weeks."

Legault thanked "my friend" Ontario Premier Doug Ford for agreeing to send medical supplies to Quebec from suppliers in his province.

A first shipment of medical supplies, including the N95 surgical masks, from Ontario to Quebec was expected Tuesday, Legault said.

He also thanked Prime Minister Justin Trudeau and Deputy Prime Minister Chrystia Freeland, who Legault said "are working very hard to secure some orders in other countries. ... It's very appreciated."

To put the demand for N95 masks in context, an internal email sent to Quebec's medical specialists Tuesday morning said Quebec used as many N95 masks last week as it did all of last year.

Legault also asked the province's health-care workers to "only use these supplies when it's necessary."

Quebec health authorities also announced six new deaths among 4,162 confirmed cases of COVID-19 as of Tuesday afternoon.

That's up six from the 25 deaths and up 732 from the 3,430 confirmed cases announced 24 hours earlier.

The 732-case daily increase is the biggest one-day rise since Quebec began issuing daily COVID-19 statistics.

There are 286 COVID-19 patients in Quebec hospitals as of Tuesday, up 51 from Monday; 82 of them are in intensive care, up four from Monday afternoon.

There are 5,601 Quebecers awaiting COVID-19 test results; 63,378 tests have come back negative.

Of the 4,162 confirmed cases in Quebec, 1,991 are in Montreal, far and away the most in any region of the province. You can find a complete regional breakdown here.

Legault on Tuesday invited Quebecers to take part in a COVID-19 clinical study previously announced by the Montreal Heart Institute.

The premier also invited Quebecers to call anyone they know who may be alone during the COVID-19 pandemic.