The massive heat wave that baked half the country in triple digit heat indexes last week may have caused as many as 64 deaths in 15 states, the National Weather Service said late on Tuesday.

Forecasters said the area still suffering from the excessive heat has diminished significantly, but some regions could suffer from a return next week.

“The high pressure system responsible for the recent heat wave will remain in place across the central U.S. through Thursday, then a brief reprieve is in store,” a National Weather Service statement said.

“The long-range forecast has heat rebuilding into the Central and Southern U.S. by early next week,” the forecast projected.

On Wednesday a portion of the Central U.S., Oklahoma, Kansas, Missouri, and Illinois, remain under excessive heat warnings. Most of the fatalities came from that region.

Livestock has also been greatly affected by the heat wave. A poll of Iowa Cattlemen’s Association members indicates as many as 4,000 head of cattle died in Iowa.

Thousands more cattle were likely killed in other states, the weather service said.

Dal Grooms, spokesperson for the Iowa Cattlemen’s Association, said farmers are doing all they can to protect their animals, but cattle are especially vulnerable as they don’t sweat and rely only on respiration.

“I’ve talked to producers who’ve been out there just constantly looking for things to do to protect those cattle,” Grooms said. “When it gets to be hot and humid like this, it is just very difficult to stop all losses.”

Some parts of Iowa last week had six or seven consecutive days with temperatures in the mid to upper 90s and heat indexes as high as 110 degrees. The state remained under a heat advisory on Wednesday.

Some other states also continued to have heat issues. In Tennessee, an air quality alert had been issued, urging those with respiratory or other health issues to stay indoors.

Temperatures were expected to reach at least 98 degrees in parts of the state with the heat index moving into the 100-plus range.

(Source: MSNBC)