Thermo Hygrometer - Temperature & Humidity ReaderThermo Hygrometer Temperature & Humidity Reader for Lash Artists The Thermo Hygrometer helps you control the two biggest factors that affect lash retention: temperature and humidity. If your room is too dry, too humid, too hot or too cold, lash adhesive can cure incorrectly, leading to poor retention, stickies and client complaints. This compact digital reader gives you accurate, real time readings so you always know if your lash room is in the