The FLIR ONE and FLIR ONE Pro LT can be used in temperatures from 32°F to 95°F (0°C to 35°C) and can detect temperatures from -4°F to 248°F (-20°C to 120°C). The FLIR ONE Pro operates at 32°F to 95°F (0°C to 35°C) and can detect temperatures from -4°F to 752°F (-20°C to 400°C).