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A PIR sensor would be the first one to look at. They are very good at sensing differences in temperature, so a warm body - even wearing clothes - will be very easy for the sensor to see.
However most of those sensors are built for single detection, like for an outdoor sensor light. They try not to detect small bodies like cats and rats and they try not to detect stationary bodies, like a warm patch of sunlight. I think your biggest problem will be the light switching off when you don't move for 10 minutes.
I've seen this used in an industrial facility. Each individual light in a large workshop switches itself on when it detects a worker moving underneath it. Then the light stays on for 10 minutes or so. The sensors look like little half-dome shapes attached to the light.
Google on occupancy sensors.
PIR are cheap but depend on movement to activate.
Architectural systems exist for business buildings but can be expensive.
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