The demand for electricity set new records and caused power outages as millions in the eastern US endured oppressive heat and humidity that was expected to continue into Thursday.

The National Weather Service posted heat warnings from Massachusetts to South Carolina and in parts of Oklahoma. Since Sunday, authorities have confirmed heat played a role in at least 13 deaths and suspect it played a role in 7 more.

The same heat wave was blamed for as many as 164 deaths last week in California.

In Boston, autopsy results were pending on a pregnant woman who died on Saturday after collapsing at a sweltering Red Sox game and suffering an apparent heart attack. A medical team was able to deliver her 1.8-kilogram infant.

In Kentucky, an 18-month-old boy was found dead on Wednesday inside a van. In Illinois, at least six heat-related deaths have been confirmed since Sunday, and police believe another six deaths in Chicago could be heat-related.

Four heat-related deaths were reported in Maryland. In Oklahoma, authorities said a 92-year-old man found near his car died of heat related-causes. In Pennsylvania, a 74-year-old custodian was found dead in his bed. An autopsy indicated he died of acute heart disease aggravated by the heat, the coroner said.

In the eastern US, the heat was not expected to break until Thursday evening, when a cold front should force temperatures down into the high 20s C, said National Weather Service meteorologist Bill Simpson.

Utility officials urged people to resist cranking up air conditioners amid heavy electric demand. Consolidated Edison, the utility that serves customers in the New York City area, set its second record in two days for peak demand. The Long Island Power Authority and ISO New England also reported record-setting energy use.

In the New York City borough of Queens, many found themselves in the dark again after recovering from a 10-day outage in late July.

Grocer Salm Ali said the power outage forced him to throw out about US$5,000 in produce on top of the US$17,000 worth of produce he lost last month.

Teams patrolled the streets of New York looking for homeless people and encouraging them to stay at air-conditioned drop-in centres. Officials in Washington also were going door-to-door to get people inside, said Mark Brown, deputy director of the city's Emergency Management Agency.

In Boston, animals at the Franklin Park Zoo were kept cool with sprinklers and frozen treats. The African wild dogs and lions got frozen blood; the primates received frozen fruit juice.

The heat was not terrible for everyone, however.

Costas Katemis, a fruit vendor outside Boston's South Station, was drenched in sweat as he handled brisk sales of peaches, plums and nectarines. But he did not mind.

"I've been here when it's been 10 below zero, and the fruit actually freezes, so this weather is no problem," he said.

Source: China Daily