Eligibility Criteria:
Inclusion Criteria:
* Non-excessive coffee drinker (\< 3 espressos / day)
* Non-smoker or weaned for 3 months and total consumption \< 10 packs/year
* With a BMI within \]18 - 25\[ kg/m².
* Benefiting from a Social Security plan or benefiting from one through a third party
* Giving free, informed and signed consent, after receiving clear and fair information about the study.
Non-inclusion Criteria:
* History of respiratory or ENT disease (asthma, chronic bronchitis, COPD, respiratory allergy, swallowing disorders, oropharyngeal malformation, obstructive or central sleep apnea-hypopnea syndrome, alveolar hypoventilation syndrome)
* Respiratory, cardiovascular, muscular, neurological or diabetic pathology or disorders
* Raynaud's disease/syndrome
* History of epilepsy or history of malaise suggestive of epilepsy
* Psychiatric history requiring hospitalization
* Liver failure
* Renal insufficiency
* History of acute mountain sickness (presence during or after a stay at altitude of symptoms of vertigo, headache, nausea/vomiting and incapacitating fatigue: Lake Louise score \> 0)
* History of migraines
* Taking medications that interfere with respiratory function or cardiovascular function, or psychotropic drugs ( anxiolytic, sedative, antidepressant, neuroleptic, muscle relaxant, etc.).
* Alcohol or drug dependence
* Anemia, sickle-cell anemia
* SpO2 \< 97% at rest in room air
* Currently participating in another clinical study
* Protected persons within the meaning of article L1121-5 to 8 (persons benefiting from enhanced protection, i.e. minors, persons deprived of their liberty by a judicial or administrative decision, pregnant or breast-feeding women, persons staying in a health or social establishment, adults under legal protection, and patients in emergency situations). - Women with childbearing capacity who do not have effective contraception (hormonal/mechanical: oral, injectable, transcutaneous, implantable, intrauterine device, or surgical: tubal ligation, hysterectomy, total oophorectomy).
* Incidental finding of acute mountain sickness (Lake Louise score \>0)
* Pregnant woman (incidental finding)
* Persistence of average sleep time \< 6h
* Non-reversible deterioration in volunteer's state of health within study period
* Electroencephalogram signal unusable