Cyber-security experts have expressed surprise that journalists at the summit between US President Donald Trump and North Korean leader Kim Jong-Un in Singapore were given USB-powered fans.
Some warned reporters not to plug them in to their laptops, as USB devices can carry malware.
The fans were part of a gift bag including a branded water bottle and a local guidebook.
Temperatures reached 33C in Singapore during the meeting.
Dutch journalist Harald Doornbos tweeted a picture of the fan.
The tweet reads: “Handy. In the press kit for the #KimTrumpSummit, there is a mini USB fan – convenient to stay cool while writing. It is pretty hot here in Singapore, 33C or so. But it does not reach Dubai, king of the oven.”
But cyber-security expert Prof Alan Woodward, from Surrey University, said: “For years now, engineering people to plug in a USB stick you supplied has been a classic way of circumventing security measures to get your software on their machine.
“There’s an adage in cyber-security: if you give someone physical access to your computer, it’s no longer your computer. Use an unknown USB stick and you are doing just that.”
North Korea has been blamed for a number of cyber-security incidents, including the release of the Wannacry ransomware that struck the NHS in 2017.
The state has denied responsibility.