The investigation was designed as an Open-Label, Multicenter, Randomised, Controlled Investigation to Evaluate the Efficacy and Safety of the BARRIER® EasyWarm Active Self-Warming Blanket Used for Continuous Active Warming to Prevent General Anaesthesia Induced Hypothermia During the Perioperative Surgical Period. Null hypothesis (H0): There is no difference between the two study populations (interventional treatment group versus control treatment group) regarding the average of core body temperature measurements during the perioperative phase.Alternative hypothesis (H1): The average of core body temperature measurements during the perioperative phase is significantly higher in the interventional group compared to that of the control group.

Inclusion Criteria:

1. Gender: Both men and women are included into the study

2. Subjects' age: Subjects must be at least 18 years old to be included into the study

3. Type of anaesthesia: Only subjects receiving general anaesthesia are included into the study

4. Type of surgery: Subjects undergoing only the following three types of surgical procedures (i.e. inclusive of laparoscopic procedures) are included into the study:

   • Gynaecological
   • Orthopaedic
   • Ear, nose and throat (ENT)

5. Length of surgery: Subjects scheduled for a surgery with a minimum length of 30 minutes and maximum length of 120 minutes

6. Temperature: Subjects should have a tympanic temperature measurement equal to or greater than 36.0 degrees Celsius when first measured in the preoperative setting the same day as the surgical procedure and before randomisation

7. Informed Consent Form (ICF): The subject must be able to understand and sign an ICF

8. Method of temperature assessment: The subject must be able to receive temperature assessments via a tympanic thermometer

9. Preoperative warming: Subject's scheduled surgical procedure must allow time to be warmed with a fully activated study Investigational Device (ID), at least 30 minutes prior to induction of general anaesthesia

10. Follow up: The subject must be able to complete a health outcomes questionnaire for follow up 24 hours (+/- 6 hours) after removal of the ID

Exclusion Criteria:

1. American Society of Anesthesiologists (ASA) Physical Status Classification rating: Subjects with a ASA rating of 4 or greater are excluded from the study

2. Comorbidity: Known Diabetes with an HbA1c of more than 6 %

3. Temperature: Subjects with a tympanic temperature measurement below 36.0 degrees Celsius taken in the preoperative setting

4. Medical history: Subject reports relevant medical history (e.g., neuropathy, peripheral vascular disease, or other) that presents risk to/of:

   1. The subject's normal temperature regulation or
   2. Perception of external temperature or
   3. Subcutaneous lipoatrophy

5. Medication: Current use of concomitant medications that present relevant risk to/of:

   1. The subject's normal temperature regulation or
   2. Perception of external temperature or Clinical Investigation Plan with Integrated Amendments 01 and 02, MD12-001, final, 14-Jan-2013 5(32)
   3. Subcutaneous lipoatrophy or
   4. All locoregional and neuroaxial blocks

6. Other:

   1. Presence of skin and soft tissue disorders in areas covered directly by the ID (e.g., pressure ulcers, clinically significant psoriasis, dermatitis or any other interruption of skin integrity that would be affected by direct heat)
   2. Known pregnancy