Needle-based apparatus having a temperature sensing function

An electrochemical sensor apparatus for contacting one or more projecting portions to a biological fluid or a tissue beneath the skin of a subject for an extended period, the apparatus comprising:

• one or more projecting portions, each configured to penetrate the skin;
• a skin contacting portion defining a skin contacting surface and one or more spaces allowing the one or more projecting portions to extend therethrough;
• a movable portion configured to move the one or more projecting portions from a first position behind the skin contacting surface to a second position proud of the skin contacting surface;
• optionally a retaining portion configured to, in use, retain the skin contacting surface in contact with the skin;
• and
• a thermal energy sensor configured to determine a temperature of the biological fluid or the tissue about the one or more projecting portions when contacting the biological fluid or the tissue,
• wherein the movable portion is configured to move from the first position to the second position.