Israeli Prime Minister Benjamin Netanyahu said Saturday he felt "very well" after being hospitalised for dizziness. This was after his office revealed that  the politically and legally beleaguered 73-year-old had likely been dehydrated.

Netanyahu had been rushed to Sheba medical centre (Israel's largest hospital) located near Tel Aviv, his office said he was in "good condition and undergoing medical evaluations".

Later the Prime Minister office said Netanyahu had on Friday spent time in the scorching heat of the Sea of Galilee, in Israel's north.

"Today, he felt slightly dizzy, and at the advice of his personal physician, Dr Zvi Berkowitz, was taken to Sheba's emergency department," another statement said.

"The initial examinations showed normal findings," it added. "The initial evaluation is dehydration."

In a video recording released several hours later, Netanyahu said he spent time on the lake with his wife "in the sun, without a hat, without water".

"Not a good idea," Netanyahu said, noting however that he was now feeling better.

"I feel very well," he said, imploring Israelis to "spend less time in the sun" and "drink more water" in the wake of the country's hot weather.

Netanyahu, who was reelected late last year, is heading a hard-right coalition whose proposed judicial overhaul has triggered weekly demonstrations since January.

The premier is also standing trial for corruption charges he denies.

In October, Netanyahu was hospitalised for overnight. His office said at the time he was feeling ill while observing the Jewish fast of Yom Kippur.