Heat and cold sensitivity in multiple sclerosis: A patient-centred perspective on triggers, symptoms, and thermal resilience practices

Background: The negative effects of heat and cold on Multiple Sclerosis (MS) have been known for ∼100 years. Yet, we lack patient-centred investigations on temperature sensitivity in persons with MS (pwMS). Objectives: To evaluate triggers, symptoms, and thermal resilience practices of temperature sensitivity pwMS via a dedicated survey. Methods: 757 pwMS completed an online survey assessing the subjective experience of temperature sensitivity. We performed descriptive statistics and regression analyses to evaluate association between individual factors and susceptibility/resilience to thermal stress. Results: Temperature sensitivity varied significantly in pwMS, with 58% of participants being heat sensitive only; 29% heat and cold sensitive; and 13% cold sensitive only (p<0.001). Yet, all pwMS: i) experienced hot and cold days as primary triggers; ii) reported fatigue as the most common worsening symptom, impacting walking and concentration; iii) used air conditioning and changes in clothing insulation as primary thermal resilience practices. Furthermore, certain individual factors (i.e. age, level of motor disability, experience of fatigue) were predictive of greater susceptibility to certain triggers (e.g. hot days) and symptoms (e.g. fatigue). Conclusion: Patient-centred evidence on the impact of and response to temperature sensitivity could play an important role in the development of individualised healthcare plans for temperature-sensitive pwMS.