['fatigue', 'overheating']
['acetylsalicylic acid at 1st visit, then placebo at 2nd visit', 'placebo at 1st visit, then acetylsalicylic acid at 2nd visit']

        Inclusion Criteria:

          -  RRMS

          -  self report of overheating during exercise

          -  low physical disability (EDSS total score 4.5 or less); fully ambulatory without aid

          -  exacerbation-free (and no use of corticosteroids) for 6 weeks prior

          -  BMI 35 or lower

        Exclusion Criteria:

          -  uncontrolled hypertension or vascular disease of the legs

          -  current medications for heart or blood pressure problem

          -  prior history of head injury, stroke, or other neurological disease/disorder

          -  currently taking antipyretics or pain medication daily

          -  presence of major depressive disorder or other psychiatric diagnosis

          -  formally diagnosed sleep disorder

          -  pulmonary disease, heart disease or other heart problem

          -  diabetes mellitus or problem with blood sugar levels

          -  lower body weakness or reliance on supportive devices for walking (as indicated
             through EDSS)

          -  counter indications to aspirin use: history of confirmed peptic ulcer,
             gastrointestinal or sever gynecological bleeding; tarry stool or fecal occult blood;
             syndrome of asthma, rhinitis or nasal polyps
      