In The Last Autumn Scenario -
Play On Easy - Puts The Regular Temperature To +10 Degrees For Most Of It.
Do Not Research The Ventilation Fans Building, Braziers, or Heaters.
Do Not Pass The Bath House Law.
^ All Of These Take Coal To Power And Will Negate The Achievement.
Building Plates For The Generator At The Foundry Is Okay.
(Even Though They Take 40 Coal Each)
Don't Get Fired (Build The Generator) And
Make It To The End (-40 Temps On Easy)
Achievement Pops When Rescue Team Arrives.
Can Be Combined With Fisherking And Arise Ye Workers (Or All Along The Watchtower).
Good Luck!