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How Hot Does a Light Bulb Get?

All light bulbs get hot when in use – that’s the nature of how they function. However, the amount of heat a light bulb emits is determined by the bulb’s wattage. A high-wattage bulb can be extremely hot and should be handled with caution.

In this blog post, we will discuss how hot a light bulb can get and give crucial tips for keeping your house safe.

Table of Contents

Does wattage affect how hot a light bulb gets?

When a 60-watt light bulb is turned on, 60 watts of electricity is converted into 60 watts of heat and light. The same applies to a 75 watts light bulb; 75 watts of electrical energy becomes 75 watts of heat and light.

How Hot Does a Light Bulb Get?

However, some light bulbs are more efficient at producing light than others. This efficiency determines what percentage of watts will be transformed into light and what percentage will be converted into heat. The main factors determining how hot a light bulb gets are the type of bulb used and the wattage.

So, How Hot Does a Light Bulb Get?

In a 60-watt, 75-watt, or 100-watt incandescent bulb, the filament temperature is roughly 4,600º F or 2,550º C, or roughly. LED bulbs the least amount of heat energy when illuminated.

Factors that affect how hot a light bulb gets

Bulb Size

A bigger bulb may get hot faster than smaller bulbs because it has a larger surface area to release and absorb heat. Therefore, large bulbs will dissipate heat more quickly than smaller ones.


If you get closer to the light bulb, the more it will get hot. This is because as your body gets closer to the bulb, its temperature also increases.

Bulb Type

A standard incandescent light produces more heat than a fluorescent bulb, meaning it will get hotter at a higher rate. Therefore, the light bulb type you choose will determine how fast it gets hot.

Bulb Age

A light bulb that has just been turned on will be hotter than one that has been lit for a while because the filament emitting the light has not attained its full temperature. Similarly, a light bulb that has just been switched off will remain a bit warm for a while.


If your light bulbs are in an area with sufficient airflow, then more heat will be able to leave. However, light with no exposure to airflow is likely to cause overheating because there is no room for heat dispensation. 

Material of the Bulb

The glass is a good light reflector and doesn’t absorb heat; this is why you won’t feel the sunlight heat coming in through the window. Conversely, the glass is an insulator, preventing heat from escaping. Therefore, you will feel the heat when there is a bright light in your room.

Distance From Object

If you want to heat an object with your bulb, the closer you get to it, the hotter it will be because the heat is concentrated in one area.

Light Bulb Shape

Halogen lights come with a thermal constant time shorter than an ordinary incandescent bulb, so they will cool down and heat up very quickly. Additionally, if your bulb is small, it will cool down and heat up more rapidly than larger bulbs because there is less material to release and absorb heat.


If you use a high-voltage system, it will increase the energy output of your light bulbs and therefore boost how fast they heat up.

How To Keep Your Light Cool

  • Keep the window next to the bulb open. This will prevent heat from escaping to the rest of the room and keep it near the bulb.
  • Keep a bowl of ice next to your light bulb to help absorb heat and cool down easily.
  • Sit close to the bulb if you are freezing.
  • Set the wattage to the lowest setting possible using a dimmer. This will also keep you warm without emitting too much light.
  • Ensure your bulb is secure. Check if the bulb is tightly fitted, and don’t cover it with anything because this can lead to an injury or accident.
  • Switch on an oscillating fan to keep yourself cool without interfering with your lamp’s temperature.
  • If the room is too hot, you can leave and go to a cooler spot. This will be more comfortable than sweating all night long.


Are light bulbs supposed to get hot?

Yes. Conventional incandescent light bulbs can get very hot because they are inefficient. Most energy produced by conventional light bulbs is wasted in heat dissipation, which is why LED bulbs are a better option.

Which bulbs give off the most heat?

Incandescent light bulbs produce more heat compared to compact fluorescent bulbs.

How Much Heat Can a Light Bulb Produce?

Light bulbs can get extremely hot. An ordinary incandescent light bulb can get hot to about 38 degrees Celsius or 100 degrees Fahrenheit, making it too hot to touch.


The type of filament in a light bulb determines the temperature of the bulb. Different filaments provide brightness and create different colors depending on how hot they get. Ensure you keep your light fixtures well-ventilated to help cool the bulbs much faster. 

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