The heat wave that has been scorching most of the country for more than a week continued undeterred Tuesday, causing severe power shortages, record-breaking temperatures and at least two deaths in the Northeast and Midwest.

The highest temperature Tuesday boiled the mercury at 112 degrees in Needles, Calif., while on the other end of the continent, New Jersey braced for its hottest day of the year, registering 97 degrees inland and on the coast by mid-afternoon. Between the coasts, the excessive heat was blamed for the deaths last week of two elderly men in Missouri.

Rapid City, S.D., had hit 100 degrees by mid-afternoon Tuesday. Heat advisories had been issued throughout the state Monday, when temperatures reached the triple digits and power consumption fell just short of breaking state records. Rapid City Regional Airport clocked a high of 101 and Ellsworth Air Force Base registered 106 degrees Monday, leading to peak alerts for area utilities including Xcel Energy, MidAmerican Energy and Sioux Valley Southwestern Electric Cooperative.

The heat appeared to be sizzling out of control in Minnesota, where 16,700 Xcel Energy customers remained without electricity early Tuesday as statewide temperatures in the 90s persisted. It was 96 degrees by 2 p.m. in Minneapolis and 91 degrees in St. Louis, Mo., a day after the Twin Cities were baked by record-breaking 99-degree temperatures Monday. In the Canadian border town of International Falls, M.N., — considered one of the coldest points in the United States — the mercury shot into the 90s for the second day, reaching 91 degrees by 2 p.m.

Forecasts by the National Weather Service offered little hope. While northern Minnesota cities can expect a slight break in the heat by Wednesday, cooler temperatures are not expected in the rest of the state until late Thursday.

In Michigan, which has been blanketed under a stifling heat wave for several weeks, the southeastern section of the state was suffering through its fifth day of 90-degree heat, while the weather up north was even worse. By 3 p.m., temperatures reached 95 in Alpena on the northern Lower Peninsula, following 100 degree peaks on Monday. No relief is expected until Wednesday, when meteorologists predict a cold front and rain will drop temperatures into the low 80s.

Detroit, battling 96-degree temperatures with a heat index of 105 Tuesday, is one of several cities that have set up cooling centers equipped with air conditioners and bottled water, and everyone from sports coaches to nursing home administrators are on alert.

"The biggest weapon is to keep everyone hydrated," said Brian Laurain, administrator of Detroit’s Fairlane Nursing Center, which has only partial air conditioning.

Blazing 97-degree temperatures hit New Jersey and New York by midday Tuesday, marking the hottest day of the year for the Garden State. In inland southern and central New Jersey, humidity brought the heat index to 110 degrees and the coastal regions were under a heat advisory.

The excessive heat was expected to drive electricity use in New York state to an all-time high Tuesday as residents sweltered from a third straight day of temperatures above 90. Demand was expected to reach 30,550 megawatts by Tuesday afternoon and the state’s Independent System Operator, which oversees electricity usage, issued a statement calling on New Yorkers to conserve however possible.

ISO spokesman Ken Klapp said the state should be able to manage the record demand for electricity, but advised New Yorkers to curb usage of major appliances like washing machines, clothes dryers and dishwashers until the evening.

New York City opened 400 air-conditioned cooling centers Monday, which officials said would remain open through Wednesday.

In New England, the temperature reached 91 degrees in Boston Tuesday, where power demands could eclipse the 24,153 megawatt record set July 25. The surge in demand sent wholesale prices for electricity soaring 351 percent Tuesday, but those prices are not expected to be reflected in consumer energy bills. Daytime temperatures are not expected to dip below 90 until Sunday. State-run beaches and pools have extended their hours until after dusk.

In Oklahoma, where forecasters had predicted temperatures would reach 100 in some parts, Oklahoma City had reached 91 degrees by Tuesday afternoon. Those temperatures are expected to persist until Wednesday, with relief arriving in the form of thunderstorms and showers in the northern and eastern parts of the state Thursday and throughout the state Friday and Saturday.

In Wyoming, where temperatures toppling 100 degrees broke four state records Monday, Tuesday was more of the same with highs expected to be near 100 in the lower elevations.

The heat is being blamed for the deaths of two Kansas City, Mo., residents last week. The Jackson County medical examiner said Monday that Leoner Mercer, 85, and George Tolbert, 77, both of whom lived in apartments without air conditioning, died from heat-related health complications. Kansas City had hit 90 degrees by Tuesday afternoon.

The Associated Press contributed to this report.