My husband creates things at home using such casting resin. He does not wear a respirator, gloves, etc. I have serached many areas of the web, but am unsure if, ultimately inhaling the fumes, or just being in the room while the 2 parts mix is harmful to one's lungs, health, etc.
PIR sensors basically detect a moving heat source when an infrared image moves across an array of sensor elements. A non-moving heat source, such as a radiator, does not trigger it. Any moving heat source will do it, including cats, dogs and so on. {Actual example: Guy falls asleep in chair after office party. Janitor thinks everyone has gone, locks up and sets alarm. Alarm doesn't go off until guy wakes up and starts moving about.} PIR sensors in intruder detectors can be triggered by something like a sheet of paper falling in front of a radiator, which causes a moving heat pattern across the sensor array even though the paper itself is not a heat source. To avoid false triggering, intruder detection PIRs are often designed to need two or more events within a few seconds to trigger the alarm. The other feature of PIR detectors is that they are better at detecting side to side motion rather than towards and away motion. A PIR's sensor array is very low resolution. The bigger the distance, the bigger the movement needed to trigger an output. Maximum range is usually about 10 yards / metres
They detect heat and it has to be moving heat for most sensors. A ball won't do anything in most cases. But depending on sensitivity a cat or a dog will set them off. If the surround temperature is about body temp (98F) people won't be detected and if it is cold but the people are all bundled up, they won't be detected. And I have fond memories of teaching in a classroom with automatic lights and a couple of times, I spent too much time standing still in the middle of the room discussing the computer task of the class and the lights shut down until I or someone moved enough to cross from one patch of the sensor to the next.
A pool would be a LOT safer than a rock pit. And there's a right way to do really serious diving - get someone who knows how to teach you and watch you.
