BEIJING, Aug. 20 (Xinhuanet) -- Two more persons in Memphis, Tennessee, were killed by the two-week heat wave, bringing the number of heat wave victims in Southeast and Midwest of the United Sates to at least 49, according to media reports Monday.

In Memphis, Tennessee, the heat-related death toll in nine days has reached to 12. Most victims were elderly and living in homes without air-conditioning.

Health officials in Alabama reported on Friday that eight people there had died of heat-related factors in two weeks.

In addition to the deaths in Tennessee and Alabama, nine have been confirmed in Missouri, four in Arkansas, four in Georgia , three in Illinois, two in South Carolina and one in Mississippi.

"It is a cumulative thing," said Dr. Franc Fenaughty, an emergency room physician in the Memphis suburb of Germantown. "After four or five or six days you are going to see more people get dehydrated. And, the big problem is dehydration."

Emergency physicians warned that the oppressive heat may lead to problems such as nausea, dizziness, headaches, cramps and vomiting for people who otherwise are healthy. Individuals with chronic respiratory or heart problems should take special precautions.

Last summer, a heat wave killed at least 50 people in the Midwest and East of the United States. California officially reported a death toll of 143, but authorities last month acknowledged the number may have been far higher. A 1995 heat wave in Chicago was blamed for 700 deaths.