Harris County Judge Lina Hidalgo issued an order on Wednesday, requiring residents ages 10 and over to wear some sort of protective face covering when in public for 30 days, effective Monday.

While face coverings have been worn by many individuals already, the new order could present some difficulty to those who have not been able to acquire a mask, or who don’t have another way to cover the face.

The order requires all people over 10 wear a mask or face covering over the nose and mouth when leaving the home. That includes in pharmacies and grocery stores, on public transit, or at workplaces in which people will be unable to adhere to six feet of social distance, Hidalgo said.

Exceptions include when eating or drinking, when exercising or doing physical activities outdoors, when alone in a single space either indoors or outdoors, at home with other people who live with you, or when wearing a face covering poses a “mental, physical, safety or security risk,” including people who have trouble breathing, according to the order.

The county will not provide any face coverings, but the city of Houston will provide a limited supply, according to Mayor Sylvester Turner.

On Thursday, after Turner’s daily press conference at 3 p.m., his office plans to announce more than 70,000 face coverings for vulnerable communities. Additionally, distributions will take place Thursday at Lone Star Community College.

If accessing those locations proves difficult, scarves, bandanas, handkerchiefs and home-made masks can be used as alternatives, Hidalgo’s office said. Her office also encouraged people not to use medical or N95 masks, so as to make them available for health care providers and first responders.

The Center for Disease Control and Prevention has proposed multiple ways to create a face covering using a sewing machine, an old t-shirt or a bandanna, which can be found here.

The CDC also provided guidance on how to wear the face covering. According to the agency, face coverings should fit snugly but comfortably against the side of the face, be secured with ties or ear loops, include multiple layers of fabric, and allow for breathing without restriction.

Masks should also be “routinely washed depending on the frequency of use,” in a washing machine if possible, the CDC said.

When removing a face covering, people should be careful not to touch eyes, nose, or mouth, and wash hands immediately after taking it off, the agency said.

Hidalgo’s office recommended, but did not order, children under 10 to wear masks. And the CDC recommends face coverings not be placed on children under the age of 2, anyone who has trouble breathing, or is “unconscious, incapacitated or otherwise unable to remove the mask without assistance.”