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Someones never accidentally touched an LED array.
I can guarantee you an LED array as big as the sun would generate enormous amounts of heat.and would need massive amounts of cooling.
Power density of the Sun is approximately 276.5 W/m³. That's counterintuitively little. A classic LED 3mm plastic package has the volume of less than 40 mm³ and some white ones can handle about 100 mW without a heatsink. Even leaving space for connections and airflow, you can easily overpower the Sun by volume by orders of magnitude.
A fun article mentioning that 276.5 W/m³ is about a reptile's metabolism (and they famously produce little body heat): https://what-if.xkcd.com/148/
On replacing the Sun with another light source: https://what-if.xkcd.com/151/
Basically, as this Stack Exchange discussion correctly states, human intuition is quite useless when thinking about things orders of magnitude outside our experience.
Meanwhile, you say "hot" because that's what your finger felt. Not really convincing of your ability to think in cosmic proportions.
So yes, LEDs are hot.
Have you touched strong incandescent lights?
Sure LED arrays are hot, but cooler than old lights
LED chips can't get above 150 °C or they fail. So high-power LED lights need appropriate cooling. And the heatsink is big and thermally conductive, making it feel hotter to the touch than it is (it delivers more heat to your finger over time). Meanwhile, the glass of some bulbs can exceed 300 °C but cools down to safe levels in a minute (or less if you touch it with something) because it's thin.
Also, 150 °C (420 K) objects do radiate heat as black-body radiation but not that much, also it's far-IR so only detectable with thermal cameras. Meanwhile, a light bulb's filament is 2700 K (3000 K in halogen ones) and the Sun's surface is 6000 K, and both produce copious amounts of near-IR light that largely contributes to the heat felt on one's skin when illuminated (although the visible light does too).
So yes, LEDs are hot.
From a human's standpoint, we say they're "hot". The fact that humans can't handle 150 °C nor 2700 °C does not mean there's no difference between the temperature of a sausage fresh off the grill and magma. (Yes, by the time it gets to the surface, lava is too cold)
So yes, LEDs are hot.
Boiling hot, as opposed to METAL-MELTING REMOTELY-SCORCHING HELL-BLAZING INFERNO
How long before you admit there is a point to calling them "cold light sources" because their color temperature is higher than what black body radiation (incandesce) can do?
So yes, LEDs are hot.
Username checks out
Try so hard to desperately disprove my point, and you fail so catastrophically that you fall into the low hanging trap that is my username.
Congrats for playing yourself.
I'm trying to get you to stop reducing temperature scale to "anything over 60 °C is hot" because it's not useful: a clearer distinction should be made between something that regularly causes house fires and something I unscrew while it's on to put under my blanket when my toes are cold. Human perception of temperature (classic 0-100 °F) just does not allow comparing things an order of magnitude higher (in Kelvin ofc). There's also more to heat, its effects and how it's perceived than a single measurement of temperature: thermal mass, conductivity, color (exchange via radiation differs between black and white bodies) etc.
Also, it's indeed ad hominem but you did choose the username yourself.
Literally all I said is large LED arrays get hot. I did not say that there is nothing hotter in the world than LEDs. I didnt say LEDs were the only source of heat in the universe. I said nothing, but that LED arrays don't run cold as the original commenter thought.
You're the one thats spent this entire time trying to "Well ackshually.." and wring your hands in desperate argument to prove a point that no one was making or even talking about.
And you want to call me an idiot for it.
You're still being reductive. An indicator LED can work without any part of it more than 10 °C above ambient temperature. No incandescent light bulb can achieve this.
And yes, there are indeed lighting systems that use many low-power LED chips spread over a large area, none of which get hot even by human standards. These cost a lot of money but last extremely long.
I'm not being reductive.
You're just being an ass.
This is the equivalent to someone asking what color is the sky. Someone saying its blue, then you coming in spending hours flailing your arms desperately screaming "THE SKY ISNT BLUE, IT ONLY APPEARS THAT WAY DUE TO THE COMPLEX NATURE OF THE INTERACTION OF SOLAR LIGHT ON THE MOLECULAR COMPOSITION OF THE UPPER ATMOSPHERE TO MAKE IT APPEAR BLUE", Then getting big mad when someone goes "So its blue then, thanks"
That's fair - my experience with handling them basically stops at individual LEDs in electronics and domestic LED lightbulbs.