As tortoises are cold-blooded animals, they rely on their environment to regulate their body temperature.
Tortoises need an external heat source, and a heat lamp gives off UV radiation, which is essential for healthy bones and shells. Unfortunately, problems can arise because tortoises need darkness to sleep.
Tortoises need a heat lamp, or an alternative heat source, at night when the temperature drops below 45 degrees Fahrenheit. If the temperature stays at this level and the tank is insulated, tortoises will adjust by burrowing into their bedding to conserve their body heat.
You can turn the heat lamp on for a limited time at night or get in a lightless heat source, like ceramic plates. You can use heating pads to warm up the tortoise, but the heat must come from above.
Do You Leave a Tortoise Heat Lamp on All Night?
Overnight heating isn’t required for a tortoise as long as these conditions are met:
- Nighttime temperatures don’t fall below 45 degrees Fahrenheit.
- The tank is insulated and holds in the heat during the day.
- The tortoise can burrow into its bedding to preserve its warmth.
If these requirements are fulfilled, don’t leave a tortoise’s heat lamp on at night. However, you can turn it on short-term to increase the tank’s ambient temperature.
When To Leave A Heat Lamp On
You can keep the heat lamp on if you’re concerned that the tortoise may get too cold at night (say, close to 50 degrees Fahrenheit). If so, setting the heat lamp at a low setting is sensible.
A temperature of at least 45 degrees Fahrenheit should enable the tortoise to maintain a normal body temperature while asleep at night.
However, if the nightly temperatures in the area exceed this range, you can turn off the heat lamp.
Is It Bad For Tortoises To Have A Heat Lamp At Night?
A tortoise’s heat lamp mimics the cycle of the sun a tortoise would experience naturally in the wild. However, the amount you use a heat lamp depends on the time of year and average temperatures.
Don’t leave a heat lamp on for more than 12 hours a day, as this could cause dehydration or heatstroke. Also, nighttime heat lamps make it harder for tortoises to sleep.
Do Tortoises Need a Heat Lamp?
Tortoises require a heat source in an enclosure because they’re indigenous to warm, dry climates.
They’re not adapted to the more temperate climates where most owners keep them. As ectotherms, tortoises require an external heat source to regulate their body temperature and digest food.
According to the Journal of Herpetology, tortoises rarely encounter heat stress in the wild, and they’re evolutionarily designed to survive or even thrive in high temperatures.
Putting the tortoise near a window is rarely enough to fulfill its needs. Likewise, even direct exposure to the sun may be insufficient during the winter or in regions where sunlight is rarely available.
Even though all pet tortoises need a heat lamp or heat source, not all have the same heating needs. Certain species require slightly higher temperatures than others.
This table shows the ideal temperature range for different species of tortoises:
| Tortoise Species | Temperature (F) | Temperature (C) |
| Red-Footed Tortoise | 90 – 95°F | 32 – 35°C |
| Juvenile Red-Footed Tortoise | 95 -100°F | 35 – 37°C |
| Russian Tortoise | 90 – 100°F | 32 – 37°C |
| Juvenile Russian Tortoise | 95 – 105°F | 35 – 40°C |
| Hermann Tortoise | 90 – 95°F | 32 – 35°C |
| Juvenile Hermann Tortoise | 95 – 100°F | 35 – 37°C |
| Greek Tortoise | 90 – 100°F | 32 – 37°C |
| Juvenile Greek Tortoise | 95 – 105°F | 35 – 40°C |
| Leopard Tortoise | 85 – 95°F | 29 – 35°C |
| Juvenile Leopard Tortoise | 90 – 100°F | 32 – 37°C |
| Pancake Tortoise | 95 – 100°F | 35 – 37°C |
| Juvenile Pancake Tortoise | 100 – 105°F | 37 – 40°C |
| Indian Star Tortoise | 90 – 95°F | 32 – 35°C |
| Juvenile Indian Star | 95 – 105°F | 35 – 37°C |
| Box Turtle Tortoise | 80 – 90°F | 26 – 32°C |
| Juvenile Box Turtle | 90 – 95°F | 32 – 35°C |
Juvenile tortoises require more heat than adult tortoises. Since juvenile tortoises are developing, they require more assistance regulating their body temperature.
Tortoise Heat Lamp Wattage
When you get a bulb for a heat lamp, you won’t find a label that states how hot it is. That’s because two heat lamps of the same wattage can give off different temperatures.
The further away your tortoise is from the heat source, the lower the temperature it’ll experience. The exact wattage of the heat bulb isn’t as relevant as how far the heat lamp is from the tortoise.
How Far Should Heat Lamp Be from Tortoise?
This table allows you to work out the correct bulb wattage to use, taking distance into account. Note the dimensions of the tortoise enclosure and the temperature needs of the tortoise.
| Wattage (W) | Distance | Temperature |
| 50W | 4″ | 104°F |
| 50W | 8″ | 81°F |
| 50W | 12″ | 73°F |
| 75W | 4″ | 120°F |
| 75W | 8″ | 91°F |
| 75W | 12″ | 81°F |
| 100W | 4″ | 131°F |
| 100W | 8″ | 113°F |
| 100W | 12″ | 90°F |
| 100W | 4″ | 144°F |
| 100W | 8″ | 131°F |
| 100W | 12″ | 126°F |
Don’t fit the heat lamp less than 4 inches away from the tortoise because it could get burnt.
Do Tortoises Need Heat Lamps in The Summer?
The tortoise may not need the heat lamp when average temperatures are higher than usual. However, it’ll need daily exposure to UV radiation to stay healthy, even when the temperatures are high.
You can start by lowering the heat lamp wattage (or increasing the distance) during the summer. After making these changes, if the tortoise remains healthy, you’ve struck the right balance.
Can You Use A Heat Mat for A Tortoise?
Heat mats or pads are heated surfaces placed on the enclosure floor. Although heat mats are used for lizards and snakes, they shouldn’t be used for tortoises.
When in use, the tortoise will sit on the mat to absorb heat when it needs to. While this may provide the ideal heating mechanism for many reptiles, it’s not beneficial for tortoises.
Heat mats don’t deliver heat in a manner that’s beneficial for tortoises. Tortoises require their heat source to come from above, while a heat mat provides heat from below.
If you use a heat mat in an enclosure, the tortoise will receive just 35% of the heat.
How to Keep a Tortoise Warm Without a Heat Lamp
There are ways to keep a tortoise warm without using a heat lamp. As mentioned, a heat mat may be okay for some reptiles, but it’s not good for tortoises. Here are some of the alternatives:
Ceramic Plates
Ceramic plates are usually screwed into the same light bulb socket used for heat lamps.
Also called ceramic heat emitters, they emit heat without visible light. According to the Handbook of Exotic Pet Medicine, this is useful when tortoises need to sleep in darkness but remain warm.
They can provide as much warmth as a heat lamp provides, creating the ideal basking environment.
Mercury Vapor Bulbs
According to the American Journal of Veterinary Research, tortoises synthesize more vitamin D3 when exposed to natural sunlight. If a tortoise can’t sunbathe, mercury vapor bulbs are an alternative.
Mercury vapor bulbs and traditional heat lamps provide heat and UVB rays. Normally, a heat lamp must be supplemented with another UVB bulb. The advantage of using a mercury vapor bulb is that you’ll only need one, saving space and lowering costs.
A tortoise doesn’t need a heat lamp at night if it can stay warm in other ways. If a tortoise gets too cold at night, offer a heat source that doesn’t generate light, such as a ceramic plate or mercury vapor bulb.
