1. Enable the display of the temperature and room humidity in the app: MENU > Set up my devices > Select your HS6 Core scale then enable Get temperature and room humidity.
2. When the scale is off, press the bottom of the scale with the foot to display the temperature and room humidity.
*credit to Sylvain of iHealth Labs EU
https://helpcenter.ihealthlabs.eu/hc/en-gb/articles/211476349-iHealth-Core-HS6-How-to-display-temperature-and-room-humidity