German Chancellor Angela Merkel appeared unsteady and was seen shaking for the second time in just over a week at a ceremony in Berlin.
The incident, which lasted around two minutes, occurred as Mrs Merkel stood alongside President Frank-Walter Steinmeier at an early-morning indoor event where Germany’s new justice minister was being formally appointed.
Mrs Merkel folded her arms across her chest while her body visibly shook, and was handed a glass of water but rejected it.
She appeared to be fine when she arrived in parliament half an hour later.
Mrs Merkel is due to set off for Japan later for the annual summit of the Group of 20 global powers.
Her spokesman Steffen Seibert told news agency dpa that “everything is going ahead as planned. The chancellor is fine”.
It is not publicly known if Mrs Merkel has any health problems.
German privacy laws are very strict on that type of information.
On Tuesday last week, Mrs Merkel’s whole body shook as she stood outside in hot weather alongside Ukraine’s president.
Mrs Merkel said afterwards that she was fine after drinking three glasses of water, which she “apparently needed”.
Hot weather in Germany has continued this week, though outdoor temperatures in Berlin dropped significantly overnight after peaking at around 37C (99F) on Wednesday.
The 64-year-old has been German leader since 2005.
Last week, dpa reported that Mrs Merkel had previously been seen shaking under similar circumstances in the hot sun.
It did not give a date for that incident, but said it was also ascribed to Mrs Merkel not drinking enough water.
However, the chancellor has a reputation for stamina garnered over years of late-night domestic and European negotiating marathons.
On Wednesday, she was on her feet in public for around two hours – first answering politicians’ questions in parliament, then giving a speech across the city.
There was no sign then of any health issues.
The chancellor has rarely had to cut back her work schedule significantly – though she did so for a few weeks in 2014 when she cracked her pelvis while cross-country skiing in Switzerland during a winter holiday.
Mrs Merkel said last year that she will not seek a fifth term as chancellor and will not seek any other political job after her current term ends in 2021.
She gave up the leadership of her centre-right party after two poor state election performances that followed a rocky start to her fourth-term government.
Mrs Merkel has shown no sign since of wanting to give up the chancellorship before her term is up.