Suplimental to [Jean-Marie Prival's answer](https://earthscience.stackexchange.com/a/22479/6031):

The February 2020 event was already discussed here in a question posted the same day this went public: https://earthscience.stackexchange.com/q/19145/6031

>[twitter.com](https://twitter.com/SMN_Argentina/status/1225455484259442691)
[wmo.int](https://public.wmo.int/en/media/news/new-record-antarctic-continent-reported)
[bloomberg.com](https://www.bloomberg.com/news/articles/2020-02-07/it-s-t-shirt-weather-in-antarctica-as-temperature-breaks-record)
[nytimes.com](https://www.nytimes.com/aponline/2020/02/07/world/europe/ap-eu-switzerland-un-antarctica.html?searchResultPosition=1)
[theguardian.com](https://www.theguardian.com/world/2020/feb/07/antarctica-logs-hottest-temperature-on-record-with-a-reading-of-183c)
>
>The tweet contained an image of a literal analogue thermometer which did show the 18.3°C... but curiously enough, also _another_ thermometer showing merely 10.0°C.
>
>[![The image tweeted by SMN Argentina](https://i.sstatic.net/7XnXh.jpg)](https://i.sstatic.net/7XnXh.jpg)

The answer to that question is that this these also form a wet-dry bulb system for measuring humidity.