Raspberry Pi 4B with and without the fan

I tried to keep my Raspberry Pi 4B device without the fan, and it reaches up to 50°C when it's hosting this experiment site pi.deepakness.com, as you see in the below screenshot.

Temperature on the Raspberry Pi 4B without the fan

But when I keep it in my room under the ceiling fan, the temperature is consistently below 40°C. By the way, earlier when it crashed, the temperature had reached over 75°C.

For now, I am keeping it without the fan but if temperature goes above 60 or so, I will place it under the fan.

Let's see.