The heat wave that snapped last week for much of the United States shows no signs of letting up soon in parts of the South and Southeast, with heat advisories in effect Monday for several states.

The high temperature in Oklahoma City on Sunday was 105 degrees, the eighth straight day and 12th time in the last 13 days that the state capital reached 100 degrees. The mercury was again to pass the 100-degree mark Monday, though there was a chance of thunderstorms.

Two additional heat deaths were announced in Oklahoma on Monday, bringing the total for the year to 20, with 18 of those deaths coming in the past month.

Even though the rest of the nation has largely seen temperatures drop, the full extent of this summer's killer heat wave has continued to be felt. More than 200 people have died across the U.S. since it began.

In New York, the medical examiner on Sunday certified 10 deaths as being caused by the heat wave, in addition to the 10 it had reported Friday. The toll could rise as additional autopsies are performed.

A man in his 80s and another in his 70s are the latest confirmed heat-related deaths in the Chicago area, bringing the total number blamed on the heat to at least 23, authorities said Sunday.

Philadelphia's medical examiner's office listed 12 more heat-related deaths, more than doubling to 21 the toll of the eight-day hot spell.

In Connecticut, Gov. M. Jodi Rell on Sunday said she wants state utility regulators to review equipment and facilities after fires in underground utility vaults caused power failures in Stamford and Meriden last week.

Heat advisories were in effect for Arkansas, Tennessee and Mississippi.