@jremington - it occured to me i could mount a MLX90614 under my sculptures (they are tripods) pointed down. Then I would only need one per tripod/Arduino, and the fixed i2c address would not be a problem. If it is 4' off the ground with a 90° FOV it should see a circle 8' in diameter. Since nobody will crawl directly under the scuplture it would only see feet and parts of legs - in other words, a very small part of the overall FOV. Do you think it is sensitive enough to reliably detect that small of a change? I know its accuracy is +-0.5°C but I wonder if with only a small percentage of hotter area if it will be able to differentiate it from ambient temp. And is the internal ambient temperature function sufficient to use as a comparison?