What Causes Fluctuating Body Temperatures In A Lung Cancer Patient?

Hi my mother has lung cancer and today when I came home she was cold and pulse was 52 bp was 94 so I kept feeding her health smoothies she perk up talk stood up some, and desire food but when I check it again her heart rate was 114. She laid down then ask me to give her what made her feel better I did, and then she said she was very hot pulling over off meaning she wasn t freezing no more.