As a reptile veterinarian, hibernation is one of the topics I get asked about most each autumn, and it is also where I see the most preventable harm. Hibernation, more correctly called brumation, is a natural process for certain temperate tortoise species, but it is not something to attempt casually. Done correctly, it is a normal and healthy part of a tortoise’s year. Done incorrectly, it can cause serious illness, blindness, or death. The risk is high enough that I always tell owners: when in doubt, do not hibernate, and ask a vet.
The two questions that decide everything are whether your species naturally hibernates at all, and whether this particular tortoise is healthy enough to do it. Tropical and desert species must never be cooled down. A sick or underweight temperate tortoise should also stay awake and warm. In this guide I will walk you through the safe process step by step, the dangerous mistakes to avoid, and exactly when you need professional help.
What You Will Need
Safe hibernation is a controlled process, not just putting a tortoise somewhere cold. Prepare these in advance.
- Confirmation that your species actually hibernates (temperate species only)
- A pre-hibernation health check from a reptile-experienced vet
- An accurate digital scale to weigh your tortoise before and during hibernation
- A reliable thermometer, ideally a min and max one, to monitor cold temperatures
- A controlled cold space, such as a dedicated fridge or an insulated hibernation box
- A clean, ventilated container with a suitable dry substrate for the tortoise
- A warm setup ready for a gradual wake-up and rehydration afterward
Never hibernate a tropical or desert species such as a sulcata or leopard tortoise, as cold can kill them. Never hibernate any tortoise that is sick, injured, underweight, or recovering from infection. Hatchlings and tortoises whose species or health status you are unsure of should also stay awake and warm. When uncertain, keep the tortoise active and consult your vet.
Step by Step: How to Help Hibernate a Tortoise
Follow this sequence carefully and never rush the cooling or warming stages. Each step protects against a specific danger.
Confirm species and get a health check
Verify your tortoise is a temperate hibernating species, then have a reptile vet confirm it is healthy and at a correct weight. Only a fit, well-conditioned tortoise should hibernate.
Fast and empty the gut
Stop feeding while keeping the tortoise warm for several weeks so it fully digests and passes any remaining food. Continue offering baths for hydration. Hibernating with food in the gut is dangerous.
Cool the tortoise down gradually
Lower the temperature in stages rather than all at once, allowing the tortoise to wind down its metabolism. A sudden plunge into cold is stressful and risky for the body.
Hold a stable cold temperature
Keep the tortoise in its container at a steady cold that stays above freezing but cold enough to maintain dormancy. Monitor the thermometer daily and weigh the tortoise periodically to track condition.
Wake and rehydrate carefully
At the end, warm the tortoise gradually back to active temperatures, offer a warm soak, and encourage drinking and eating within a day or two. A tortoise that will not eat or drink after waking needs a vet.
Common Mistakes to Avoid
These are the errors I most often see cause hibernation tragedies, and every one of them is avoidable.
Cooling a tropical species, hibernating a sick or underweight tortoise, and failing to empty the gut first are the most serious. Letting temperatures swing or drop to freezing can cause irreversible damage including blindness, while temperatures that are too warm burn through body reserves and starve the tortoise. Skipping weight checks means you cannot tell if the tortoise is in trouble, and not having a warm wake-up plan leaves a dehydrated tortoise without support.
People also commonly guess at temperatures with no reliable thermometer, or use an uncontrolled garage or shed where cold snaps can freeze the animal. Hibernating for far too long, especially as a beginner, adds unnecessary risk. When any of these conditions cannot be met, it is safer to keep the tortoise awake and warm through winter.
Tips for Success
These habits make hibernation far safer and let you catch problems early.
Use a controlled fridge or insulated box with a reliable thermometer rather than an unpredictable shed. Weigh your tortoise before hibernation and check it periodically. A small steady weight loss is expected, but rapid loss means you should wake the tortoise and call a vet. Keep the hibernation period controlled and on the shorter side if you are new to it, and always have a warm recovery setup ready before you start.
Check on your hibernating tortoise regularly without overly disturbing it, watching for any sign that it has woken, urinated, or lost too much weight. If a tortoise urinates during hibernation it loses vital water reserves and should be warmed up, rehydrated, and not put back into hibernation that season. Keep good records of dates, weights and temperatures.
When to Get Professional Help
Hibernation sits firmly in the territory where veterinary guidance prevents disasters, so do not hesitate to ask.
- You are unsure whether your species should hibernate at all
- Your tortoise seems unwell, underweight, or has any swelling or discharge
- Your tortoise urinates during hibernation or loses weight rapidly
- You cannot maintain a stable safe temperature above freezing
- Your tortoise will not wake, eat, or drink properly afterward
- The eyes look sunken, cloudy, or there are signs of a respiratory infection
A reptile-experienced vet should ideally check your tortoise before hibernation and is essential if anything goes wrong during or after it. Pre-hibernation exams catch hidden illness that would make cooling dangerous. If your tortoise wakes early and eats something questionable while exploring, you can also reach the ASPCA Animal Poison Control Center at 888-426-4435.
Safety note: Only hibernate a confirmed temperate species that a vet has assessed as healthy and correctly weighted, and never cool a tropical, sick, or underweight tortoise.