Nevada sizzled on Wednesday as temperatures approached record highs and forecasters warned of even hotter conditions through the end of the week.

The National Weather Service issued a heat advisory for western Nevada and the eastern Sierra, where temperatures were expected to top the century mark through Friday.

In southern Nevada, an excessive heat warning was issued Tuesday through Friday, and forecasters warned of "dangerously hot" conditions.

"We put this warning out especially for the elderly and people who are vulnerable to this," said Charlie Schlott, a meteorologist with the National Weather Service in Las Vegas.

"You have to use common sense when out and about in this heat," he said. "You can become dehydrated really quick before you know it. You step outside and, 'wow.' "

Officials also warned against leaving pets and children in vehicles, where temperatures can quickly turn fatal.

Health experts said the best way to avoid heat-related illnesses is to limit time in the sun, wear light-colored clothing, avoid alcohol and drink lots of water.

Temperatures in Las Vegas were expected to reach 116 degrees Thursday and tie the record for the date set in 1985.

The all-time high for the Las Vegas Valley since official record keeping began in 1937 is 117 degrees on July 19, 2005, which tied the extreme high temperature record set on July 24, 1942.

In Reno, Thursday's high was expected to top out at 105 - five degrees hotter than the previous record for the date set in 1970.

Forecasters predicted the temperature in Lovelock on Thursday to hit 108 and break the old record of 104 that was reached in 1991.

Northeastern Nevada also braced for scorching temperatures.

"Record high temperatures between 100 to 105 degrees are expected Thursday and Friday afternoon, with a few lower valley locations possibly reaching 110 degrees," the weather service in Elko said in a special weather statement.

Not even the mountain communities around Lake Tahoe were immune from record heat.

At South Lake Tahoe, the weather service predicted Thursday's high would reach 93 degrees and shatter the old record of 88 for the date set in 1991.