The weekend’s heat wave contributed to at least two deaths Saturday, bringing the total of heat-related deaths this season to three, according to autopsy reports from the Cook County medical examiner’s office.

Bettye Richmond, 71, and 54-year-old James Alighire died July 20, the medical examiner’s office said.

Richmond died about 9:50 p.m. in the 3300 block of West Polk Street. in Homan Square on the West Side, the medical examiner’s office said. Alighire died about 3:41 p.m. at Swedish Covenant Hospital.

The primary cause of death in both cases was coronary atherosclerosis, the medical examiner’s office said, but “heat stress” was a contributing factor in both.

Earlier in the month, 87-year-old Leona T. Serafin died in Bucktown on the North Side, the medical examiner’s office said. She was pronounced dead July 5 in the 2100 block of West Shakespeare Avenue and died from organic cardiovascular disease with probable heat stress as a contributing factor.

The National Weather Service issued an excessive heat warning from July 18 through July 20. On July 19, the temperature in Chicago never dipped below 81 degrees — a new record low for that day.