Some devices can be placed on the chest wall to allow monitoring of the patient. These include Electrocardiogram leads and temperature probes.
A patient in hospital often requires continuous monitoring of their heart rhythm particularly if they are suffering from chest pain, have a cardiac abnormality or are very sick in Intensive care. The patients will require Echocardiogram stickers and leads on their chest wall. These can be seen on a Chest X-ray.
Here is a patient on the Medical Critical Care Unit with ECG leads on the outside of the chest.
A patient in an ITU setting may well have a temperature monitor attached to the skin.
This baby in the Neonatal Intensive care unit has a temperature probe (green) placed on the skin under the left axilla.
In adults in the intensive care units, they are sometimes placed within the oesophagus to obtain a core temperature reading.