Sentence 1: Joan was always cold and her husband was always hot. 
 Sentence 3: Both agreed to compromise by setting it at 68 degrees 
 Sentence 4:  When Joan still felt cold, she got suspicious 
 Sentence 5:  She saw her husband had written 68 at the 60 degree mark 
 Option 1: The thermostat became their biggest battleground. 
 Option 2: Joan agreed to always wear sweaters so they wouldn't have to fight over the thermostat.