State health officials have issued an advisory for those areas of northern New Mexico that are affected by smoke from two wildfires.
The state Department of Health says the communities that are most affected include Pecos, Jemez Springs and La Cueva.
Visibility could be reduced to less than 3 miles and potentially unhealthy conditions could occur overnight and into the early morning.
Health Secretary Retta Ward says the smoke can irritate a person's eyes and respiratory system as well as intensify chronic heart and lung problems.
Officials are urging people who are sensitive to the smoke — including pregnant women, the elderly and young children — to limit their time outdoors. Any time visibility drops under 5 miles, officials say air quality is considered unhealthy for sensitive groups.