Players get punished for having a dangerous temperature. They can also optionally be rewarded for having a good temperature. All these effects can like always be changed in the configuration.
Freezing and half a heart damage every 2 seconds (see screenshots).
Air temperature below 0°C
Disabled by default, any potion effect you want. Could be something like
Burning (see screenshots)
The plugin will warn players if they reach dangerous temperatures through the action bar and chat. This can be configured. See screenshots below.
Freezing effect. The screen effect won't be displayed in 1.16.