There are many difficult achievements in "Frost Age 2", and adapting to the weather is one of them. To achieve this achievement, you only need to achieve "no disease" and "no disease" for 20 consecutive weeks when the temperature is at least -100 degrees Celsius. "No cold" is very difficult and you need to prepare a lot of resources.
How to get the Adaptation to Weather achievement in Ice Age 2
Adapt to the weather
Achieve 20 consecutive weeks of "disease-free" and "cold-free" when the temperature is at least -100 degrees Celsius
Survive 20 consecutive weeks at -100ºC without disease or cold.
Make sure you have enough shelter and fuel to survive the White Curtain, and plenty of food, otherwise diseases will appear one after another.
