Amyotrophic lateral sclerosis (ALS) is the major adult-onset motor neuron disease, and is clinically, pathologically, and genetically associated with frontotemporal dementia, the second cause of dementia in the elderly. Here, we review the evidence linking thermoregulation and ALS. Indeed, while ALS is not classically associated with defective thermoregulatory function, its progression severely affects key brain regions controlling body temperature and impacts multiple sensors and effectors of this homeostatic function. Furthermore, animal models of ALS display disturbed thermoregulation as a consequence of disrupted energy homeostasis. All these lines of indirect evidence call for studies directly addressing the body temperature regulatory system, both as a potential biomarker and as a possible modifier of disease progression in ALS.