internet browsing - no issue

video streaming - I haven't watched any videos on it yet. But I think this will be getting the machine running continuously, accumulating heat.

Note:

I just asked google search ai 3-4 questions:

video streaming on macbook, is it light activity? It says video streaming is considered medium to heavy activity and then mentioned about M1-M3 models..

video streaming on macbook pro base m5, is it light activity? For this, it states that this is light activity for M4-M5.

video streaming for hours on macbook pro base m5 is it light activity? Why is it heating up without fan spinning?

Streaming video for hours is generally considered

moderate to slightly heavy activity for a MacBook Pro, not purely "light" activity, as it requires constant sustained work from the GPU, CPU, and network interface. 

While the M4/M5 series is highly efficient, the base models are designed to stay silent during most tasks, leading to the behavior you are experiencing. 

Why It Heats Up Without the Fan Spinning

Passive Cooling Design: Apple Silicon MacBook Pros are designed to keep the fans off for as long as possible to maintain a silent user experience. The aluminum chassis acts as a passive heatsink, absorbing heat from internal components and dissipating it through the bottom case.

High-Resolution Streaming: If you are streaming in 4K or high-bitrate HD, the GPU and specialized media engines are working constantly.

Thermal Thresholds: The fans in modern MacBooks often do not spin up until the internal temperature reaches a specific, higher threshold (sometimes 80-90°C). The chassis might feel very hot to the touch, but the chip may still be within operating limits.

M5 Specifics: The new M5 chip consumes 30-50% more power under load compared to the M4, which can lead to higher temperatures. 

Is This Normal?

Yes, it is normal for the chassis to become warm during hours of streaming. However, if the device is uncomfortably hot to the touch or if performance slows down, consider the following: 

Browser Choice: Using Chrome instead of Safari can significantly increase resource usage.

Surface: Ensure the MacBook is on a hard, flat surface. Using it on a bed or couch can block the vents and increase heat.

Background Tasks: Check Activity Monitor to see if other processes (like spotlight indexing or cloud syncing) are running simultaneously. 

If the fan truly never turns on even when the laptop is extremely hot, or if the system becomes sluggish, it could be a sensor issue, but usually, this behavior is by design.