The Maine Center for Disease Control and Prevention is warning residents to take precautions when they venture outside due to the public health threat posed by browntail moth caterpillars.

The greatest risk for exposure to the browntail moths’ toxic hairs is between April and July, the CDC said.

Outdoor activities such as mowing the lawn, raking and sweeping can stir up hairs, which have been known to linger on lawns, gardens, outdoor furniture and decks.

Browntail moth caterpillars shed tiny toxic hairs that can cause a skin rash like poison ivy. The hairs can remain toxic in the environment for up to three years and when the hairs become airborne they can cause breathing and other respiratory problems if inhaled.

Most individuals affected by the hairs develop a rash that can last for a few hours up to several days. In more sensitive individuals the rash can be severe and last for weeks. The Maine CDC says browntail moth caterpillars are dark brown with white stripes along the sides and two red-orange dots on the back.

Steps that Mainers can take to protect themselves include: working outside on damp days or spraying vegetation down. The moisture will help keep the hairs from becoming airborne. Covering your face with a respirator and goggles helps as do taking a shower and changing clothes after working in an infested area.

The Maine Forest Service has found evidence of browntail moths in all 16 Maine counties.