Why Exactly Does Heat Trigger Pain in Multiple Sclerosis Patients?

Fatigue is a common symptom that is experienced in around 70% of individuals with MS. Being that the limbs are already weakened due to MS, a slight increase in temperature can aggravate them, thereby triggering the onset of fatigue. Pain is another common symptom that worsens with elevated temperatures. Several studies propose that the reason behind this may be due to the damage caused to the thalamus and the spinothalamic-cortical pathways, thereby leading to thermoregulatory dysfunction.

Cognitive functions in individuals with MS are also sensitive to heat and can lead to decreased concentration, memory problems, judgement difficulties, as well as problems with other cognitive skills. In fact, a recent study found that individuals with MS experienced a worsening of cognitive functions during warmer days.