Rationale: Chronic fatigue syndrome (CFS) is a complicated disorder characterized by severe fatigue that is not relieved with rest and associated with physical symptoms such as sleep problems, headache, muscle pain, or joint pain.
Patient concerns: Forty-one year old patient complained from feeling cold after breast cancer surgery.
Diagnoses: The diagnoses of fibromyalgia, depression, neurological, psychiatric, and vascular disorders were excluded by appropriate clinical and laboratory investigations. She was diagnosed as CFS.
Interventions: The patient was treated successfully via aerobic exercise therapy that scheduled for 30 min at least 3 days per week.
Outcomes: At 6-month follow-up, her complaints were almost resolved and the patient regained her physical health and mental attitude.
Lessons: A thermal dysregulation should be taken into consideration as one of the symptoms of CFS.