Wearing a mask is just, plain sensible. But too many Oregonians don’t wear masks. We can’t let the sacrifices people have made during the pandemic be for nothing.

The Oregon Health Authority says modeling shows the coronavirus infections could have exponential growth in the middle of July. That could mean enough patients would need to be hospitalized that hospitals would again have to start limiting nonurgent procedures. Gov. Kate Brown could feel the need to reinstate limits on public gatherings.

“I am asking Oregonians to take this very, very seriously,” Brown said recently. “The increase in cases is alarming. We have done a really good job so far.”

“If we continue on this path, we will have to button down the economy,” she added.

Nobody wants to go back to lockdown mode. Brown announced Monday she was requiring the public to wear masks in all public, indoor spaces, including businesses.

Of course, modeling can be off. But cases have mounted since reopening. We need to take the modeling as a reminder to follow the recommendations that have been successful to limit the spread of the virus.

Wearing a mask for Halloween can be fun. Wearing a mask for the coronavirus is not. Masks are itchy. They can cause a rash. They muffle speech. They can make your glasses fog up. They can make breathing uncomfortable.

But wearing masks and social distancing do work. The virus does kill people or can at least make them sick. People can show no symptoms and still be infected.

Reporters and editors from The Bulletin went out one day last week in a coordinated effort to get some sense of how many people were wearing masks. Slightly more than half of customers entering were wearing masks in the eight grocery stores the staff visited.

Nobody is claiming that was a scientific survey. It was a crude snapshot. Isn’t it disappointing, though, that the numbers of people wearing masks weren’t higher?

It’s been a relief that the shutdown and the distancing requirements have eased. Let’s not go backward. So please wear a mask and maintain social distancing.