Nowadays, the Internet of Things (IoT) has an astonishingly societal impact in which healthcare
services stand out. Amplified by the COVID-19 pandemic scenario, challenges include the development
of authenticatable smart IoT devices with the ability to simultaneously track people and sense in realtime human body temperature aiming to infer a health condition in a contactless and remote way through
user-friendly equipment such as a smartphone. Univocal smart labels based on quick response (QR) codes
were designed and printed on medical substrates (protective masks and adhesive) using flexible organicinorganic luminescent inks. Luminescence thermometry and physical unclonable functions (PUFs) are
simultaneously combined allowing non-contact temperature detection, identification, and connection with
the IoT environment through a smartphone. This is an intriguing example where luminescent inks based
on organic-inorganic hybrids modified by lanthanide ions are used to fabricate a smart label that can sense
temperature with remarkable figures of merit, including maximum thermal sensitivity of Sr = 1.46 %K−1
and temperature uncertainty of δT = 0.2 K, and an authentication methodology accuracy, precision, and
recall of 96.2%, 98.9%, and 85.7%, respectively. The methodology proposed is feasibly applied for the
univocal identification and mobile optical temperature monitoring of individuals, allowing the control of the
access to restricted areas and the information transfer to medical entities for post medical evaluation towards
a new generation of mobile-assisted eHealth (mHealth).