Providing The Right Heat and Light for Your Pet iguana

The number one illness that affects pet iguanas is Metabolic Bone Disease (MBD). This is a crippling disease that is usually caused by improper lighting. An iguana will only begin to show signs of MBD after it’s already fairly severe, this is why it is absolutely important to make sure you are providing your pet with the correct heat and lighting — if you don’t, they will get sick! This means providing a light source for both UVA and UVB wavelengths!

UVB light is necessary to ensure proper production of Vitamin D and optimum calcium absorption in iguanas (and other animals too, including humans). A pet iguana simply will not survive more than a few years if you do not provide the proper levels of UVB lighting!

You must make sure your pet iguana’s habitat has the correct heat and light to make sure that they stay healthy. This is not something that you can ‘upgrade later’ or ignore when you set up an iguana’s habitat or enclosure.

How Much Light Does an Iguana Need?

Iguanas need 12-14 hours of light and 10-12 hours of darkness each day. Some people suggest adjusting the light cycle with the sunrise and sunset, but if you live in a place far from the natural habitat of iguanas it will not be a very good practice to do it that way.

You should keep your lights on a timer so that you don’t forget to turn the lights on or off at the right times each day. Setting up a timer to do this is very easy to do, there are several kinds of timers and all of them are very simple to use. I suggest you get a few of them, you’ll find all sorts of uses for them.

Click here to buy a good timer from Reptile Supply.

What Type of Light Do Iguanas Need?

The best type of light for an iguana is the specially designed MegaRay bulbs. I currently use the MegaRay bulbs because they are the best I have been able to find over several years of iguana keeping. Before I found the MegaRay bulbs I used ZooMed’s Powersun UV 100 watt bulbs, but since I discovered the MegaRay I haven’t gone back. The Zoo-Med bulbs are good but they don’t last as long as the MegaRay brand and need to be changed more often.

These lights provide the best UVB ranges out of all others on the market as far as I know. These powerful mercury vapor bulbs should be at least 12 inches away from the basking area in your enclosure. You should be positive that there is absolutely no way your iguana can get closer to the bulb than 12 inches, or your iguana will get too close and burn itself.

This is very important, getting the bulb closer doesn’t do your iguana any good — it actually hurts them, so don’t let them get any closer than what is recommended for your specific bulb and wattage. I use the 100W MegaRay’s and they work just fine for me at 12 inches from the basking area.

Do not use plant lights, ‘grow lights’, or fluorescent bulbs for your iguana. These bulbs will not provide the right amounts of UVB light to sustain an iguana — your best option is to go with a MegaRay or PowerSun bulb and to set it at an appropriate distance from the basking area.

Where to Place the Bulb?

Don’t put your lights behind glass or cages with spaces smaller than 1 inch between the bars. The UVB wavelengths that are required by a healthy iguana will not go through glass or cages with small spaces or screens.

Visible light can go through glass and small screens but the important UVB wavelengths can not get through, so an iguana with its light located behind a screen or glass will eventually get sick with Metabolic Bone Disease (MBD) because it’s not getting the essential UVB rays that it needs to thrive — even when the bulb is the right type.

Read more on Metabolic bone disease in iguanas.


If you can, you should let your iguana get some real sunlight from time to time. Nothing beats mother nature, so providing a basking area in the sun on a nice day is a great idea too, but be sure to provide a cool spot too so your iguana doesn’t overheat! There should always be a way for your iguana to get out of the heat if they get too hot.

It is possible to get ‘greenhouse glass’ that allows UVB wavelengths to pass through it. This would be a good idea if you have a window that gets a lot of sun — you could install a window with greenhouse glass and put a basking ledge by it for your iguana if you feel so inclined. I’m sure any iguana would love a special area like that!

It’s also important to note that if you’re putting your iguana outside, you want to make sure they can’t get away! They can be fast when they want and are good climbers, you don’t want your iguana running up a tree that you can’t get to! Make sure you have an outdoor enclosure that is closed securely if you’re taking your iguana outside!

Do Iguanas Need Night Lights?

Does an iguana need a nightlight? Many people like to provide their pets with a night light during sleeping hours, but I don’t usually bother with this.

Unless the area that your pet is located in has no windows or natural light that can get in, I don’t think a night light is necessary. If your iguana is in a room with no windows, or a room that has been meticulously light proofed, I would consider adding some sort of night light in case your iguana wants to move around in the dark and is unable to see where it’s going.

I used to use a light fixture that would glow in the dark after the light went off, but I recently switched to a deep dome light fixture because it’s safer than the glow in the dark one — I liked the glow in the dark one because it eliminated the need for any kind of night light — even in the darkest room in the house. But the bulb was slightly longer than the dome, so the end of the bulb would stick out a bit, so it was in constant danger of being accidentally smashed or touched.

How Iguanas Feel Heat?

Most people don’t know this, but iguanas don’t feel heat on their skin like humans do. They don’t have the same kind of heat receptors in their skin as we do, and they feel temperatures based on their ‘core’. This is why iguana’s are so easily burned by getting too close to or even touching things like extremely hot mercury vapor bulbs or heat lamps.

Iguanas heat receptor is at the base of their brain, so they only feel how hot it is at the base of their brain. This means if something is burning the bottom of their belly or their leg, they might never even feel it! That’s why they don’t move away from something hot on their skin like a human would. This makes it extremely easy for an iguana to burn itself without even knowing it.

It’s not that the iguana is stupid — their bodies are not built to feel heat on their skin like ours! They feel heat from the core of their body which means their skin could be far hotter than the inside of their body at the base of their brain.

How Much Heat Does an Iguana Need?

Since your pet iguana actually originates in a much more tropical environment than most indoor habitats it is important to make sure your iguana has a basking spot where they can reach at least 32 Celsius (90F). This is important because iguana’s do not adjust their body temperatures like mammals do, they rely on their environment to regulate their body temperature. 32 C / 90 F is a minimum temperature and you should be aiming for a basking spot that reaches 35-38 degrees Celsius or 95-100 degrees Fahrenheit.

If an iguana can not reach at least 32 degrees Celsius or 90 degrees Fahrenheit they can not properly digest their food. If your iguana can’t digest its food, it’s going to get sick and could die. This is why regulating the temperature and physically checking it with thermometers to make sure the temperature is right is so important.

You can get ‘temperature guns’ that can read the temperature of your iguana’s body by simply pointing it at your iguana. You should check the enclosure’s temperature with multiple thermometers and you should also check different areas of the enclosure and not just the basking area.

You can click this link for a Neiko Non-Contact Infrared Thermometer with Laser Aim on Amazon.com. It’s a really useful tool to have when you’ve got exotic pets like a green iguana. You’ll find a million ways to use it and won’t be disappointed.

Do Iguanas Need Heat at Night?

It’s important to measure your habitat temperatures at all times of the day. There are thermometers that will record high’s and lows and at what times they were reached — I suggest finding at least one thermometer with this option to leave in your enclosure so you can be sure your temperatures are consistently in the correct range.

A drop of about 5 degrees Celsius or 10 degrees Fahrenheit is acceptable for night time temperatures. Your iguana’s enclosure should never drop below 26 C or 80 F, so it is important to provide a heat source not only during the day, but at night as well.

Safe Heat Sources for Iguanas

There are many ways to provide heat for your iguana, but some are better than others. It’s important to remember that no matter what heat source we are talking about, safety is always an issue. Always be 110% sure that there is no chance your pet may get burned or overheat. All heat sources should be placed so that your pet cannot get into direct contact with them. Your pet should never be able to touch any of the heat sources in its habitat.

You may want to consider putting cages or wire mesh around your heat and light sources to ensure your pet can not touch them no matter how hard they try. Also, make sure they cannot get on top of heat sources or lights, this is very dangerous and should be avoided at all costs!

The main source of heat that I use for my iguana is the basking light itself — the MegaRay and PowerSun bulbs both put off a lot of heat. It’s important to make sure your iguana will not get too hot though, so a balance of light and heat is important. Always make sure your bulb is properly distanced from the actual basking area so it does not burn your pet!

Ceramic Heaters

Another good source of heat is ceramic heaters. A good ceramic heater comes on when the temperature drops below a pre-set temp. It will turn on for a few minutes, heat up the area, and then turn off when it’s warm enough. They are most effective if the area you are heating is enclosed though, you don’t want to run one of these things 24/7 because they can suck an awful lot of power.

I’ve used a ceramic heater for quite a while now and I noticed a big difference in the way my pet iguana was acting after I started using it. She loves her ceramic heater! I would recommend setting your ceramic heater to about 26C or 80F for a decent night-time-low temperature.

Heating Bulbs

Another option is ‘heat bulbs for reptiles’ which work like light bulbs that don’t produce any light. They screw into regular light fixtures and just emit directed heat in whatever direction you point them. I don’t use these myself, but I have some friends who use them and say they work fairly well, but I’ve never found the need for them in my enclosures.

Heating Pads

Heating pads for humans are also an option but should be used only as a last resort. Do not leave heating pads unattended, or on high settings. It could do more harm to your iguana than it does well if you leave it on high or without supervision. Heat pads can be used to help tend to sick iguanas and should be used only if absolutely necessary. There are better ways to provide heat to your iguanas.

Dangerous Heat Sources

Some heat sources are dangerous and should be avoided. Unfortunately, many dangerous heat sources are recommended at your local pet stores and could potentially harm you or your pet. Here I’ve listed some of the sources that should be avoided.

Heat Rocks

Avoid using heat rocks that are sold in nearly every single reptile supply shop on the planet. I don’t know why stores still carry these products, or why the companies that make them are still in business. Pretty much every knowledgeable reptile owner is in agreement that heat rocks are extremely dangerous and should be avoided.

Heat rocks get too hot and will burn your pet. The package has clever marketing, making it seem like a replacement for natural rocks that have been heated by the sun in nature. In nature, iguana’s don’t sit around on hot rocks — they climb trees and eat leaves all day. It’s not a natural source of heat for an iguana to be heated from underneath.

Iguanas bask in the sun to be heated from above, not on rocks to be heated from their undersides — plus, the heat rocks get far too hot and will result in physical burns on your iguana’s belly! Do not use these things! If you have one, return it to the store and tell them you want your money back.

Reptile Heating Pads

The heating pads sold in the reptile supply section of the pet stores are just about as bad as the heat rocks on the shelf next to them. If you’re set on using some sort of heating pad for your iguana, use a high-quality one that is made for humans, not for pets. The pet versions are cheaper and more dangerous than the ones made for humans.

Heat Ropes and Other Strange Heat Sources

There are many types of heat cords and other weird sources of heat that might look good at first glance but then turn out to be not so good. I wouldn’t recommend using any obscure heat source that you aren’t sure of. There are several safe and reliable methods to heating your iguana’s enclosure — you shouldn’t risk using some impulse bought doohickey for heat, it’s probably not a good idea.

I do want to mention that I have used a heat cord that did temporarily add heat to my iguana’s enclosure from time to time. This is only when I have been in between moving to a new home, etc, and have not been able to set up her ceramic heater that she so loves.

I have put a heat cord weaved underneath the bottom of the basking area to provide additional heat as a temporary solution. The cord is weaved through a piece of cage that has 2 inches of fake grass-like stuff on top of it so there is no way that my pet iguana can touch the cord itself.

It raises the temperature of the basking area enough to keep it around 26-27 degrees Celsius at night which is perfect as a temporary solution. I wouldn’t recommend something like that as a permanent heat source though.

Do Iguanas Overheat?

It’s important to make sure that your iguana is always kept fairly warm, but with that said, it’s also very easy to get your iguana too hot, and then it begins to overheat. Overheating is dangerous. It doesn’t take long for a little overheating to become unbearable for your iguana and it could die in a very short period if it has no place to go to cool down.

Always make sure that your iguana’s enclosure has both warm and cool spots so that it can move out of the heat if it’s too hot or into heat if it’s too cool.

If your iguana is breathing with its mouth open or is panting, that means it is too hot! Give your iguana someplace to cool down if it gets too hot. Do not splash it with cold water, toss it in a pool, or otherwise cause it any kind of ‘shock’.

This won’t do your iguana a whole lot of good and will just frighten it. Make sure your enclosure has a cool area where your iguana can get away from the heat and cool down if it starts to overheat.


Use common sense and safety practices when setting up your iguana’s habitat, especially when it comes to heat and lighting. These two elements can be extremely dangerous if you don’t take care of them responsibly.

Make sure that cords are organized and put out of the way where your iguana can’t get tangled or injured, make sure electrical plugs and water don’t get close to each other. Make sure that your iguana can’t stick its tail in a fan or on a light bulb or heater. Inspect your enclosure and think about what you’re trying to do.

Always keep safety in mind when setting up an enclosure or a new heat or light source for your green iguana.

If you have any questions you can always ask in the comment box below this post.

Filled under: Lizards

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