Cristopher Soto of Hartford found the perfect spot to stay cool during a 2018 summer heat wave in the city. (Courant file photo) (Stephen Dunn)

Scorching heat is expected throughout Connecticut on Saturday and Sunday, and state officials urged people, including those headed for relief in still frigid fresh or salt water, to be safe.

Temperatures in much of the state will be in the low to mid-90s both days, 20 degrees higher than normal, and the state’s usual hot spots, including Windsor Locks, could reach 100, meteorologist Gary Lessor said Friday. The shoreline will be a bit cooler, with temperatures in the 80s, Lessor said. Cooler, less humid weather is forecast for Monday.

Further, the state Department of Energy and Environmental Protection said it is expecting the very warm weather to contribute to “elevated ozone levels across much of Connecticut.” The levels may approach or exceed “unhealthy for sensitive groups” levels for parts of Connecticut on Saturday May 21, the agency said

“With summer–like temperatures expected this weekend, more people will be taking to the outdoors for all types of recreational activities, including visiting one of Connecticut’s many beautiful beaches or state parks,” said DEEP Commissioner Katie Dykes, in a release. “As our weather warms up, all the conditions for ozone production are in place and we expect to see elevated levels across coastal towns extending from Greenwich to Stonington, up to East Hartford Connecticut.”

The water temperature in New London on Friday was 57, Lessor said, and water temperatures on the shore and inland will remain much colder than in the summertime, the state Department of Energy and Environmental Protection cautioned.

Most people will find the water too cold, and there is also “a very real danger of hypothermia for swimmers, particularly children, who enter the water for any extended period of time,” the agency warned in a news release Friday.

Also, no lifeguards will be on duty this weekend at state parks, DEEP officials said, and water safety is everyone’s responsibility.

The agency also reminded boaters that cold water temperatures create substantial dangers to the unprepared. Paddlers should exercise caution and use proper equipment, practice safety techniques, wear life jackets and avoid dangerous situations. Paddlers should always be ready for a sudden cold-water immersion.

Over the last six years, Connecticut families have grieved the deaths of seven paddlers during spring’s cold water boating season, according to DEEP. To learn more, visit portal.ct.gov/deep.

Officials in Hartford and other communities are offering cool refuge in public buildings. Hartford plans to open four cooling centers, and city firefighters will hand out water to residents throughout the city.

“Please stay out of the sun during the hottest parts of the day,” Hartford Mayor Luke Bronin said, “and please remember to check in on your loved ones and neighbors, especially seniors, who may be particularly affected by the heat.”

The Hartford Public Library, 500 Main St., will be open as a cooling center on Saturday from 9 a.m. to 6 p.m. On both Saturday and Sunday, cooling centers will be at North End Senior Center, 80 Coventry St., open from 10 a.m. to 6 p.m.; South End Senior and Wellness Center, 830 Maple Ave., 10 a.m. to 6 p.m. and Asylum Hill Church, 814 Asylum Ave., noon to 5 p.m.

In Simsbury, the library will be open Saturday from 9:30 a.m. to 5:30 p.m. and Sunday from 1-5 p.m. In West Hartford, splash pads at Fern, Kennedy, Beachland and Wolcott parks will be open on Saturday from 10 a.m. to 7 p.m. Bloomfield will open its cooling centers at both its libraries and at the Alvin & Beatrice Wood Human Services Center.

People are urged to avoid prolonged sun exposure and to keep hydrated. Early morning and evening are the best times to be outside, so plan the day accordingly. Also, check on elderly family members and neighbors, and never leave children or pets in unattended vehicles.

Jesse Leavenworth can be reached at jleavenworth@courant.com.