Inclusion Criteria:  Provision of informed consent Adult males and females ≥ 18 years old Able to maintain a supine position up to 10 hours.  Exclusion Criteria:  Diseases/medical treatments that affect normal body temperature control:  I. Persons who have/have had thyroid disease or who are treated with medications affecting the thyroid hormones  II. Persons being treated with medication affecting normal body temperature control, based on investigator judgement.  Impaired circulation/vascular disease Impaired sensitivity/neuropathy Active skin disease Female with temperature variations due to menopause Pregnancy or lactation at time of study participation. Person not suitable for the investigation according to the clinician's judgement.