Tortoise Hibernation in the UK: Complete 2025 Guide (Fridge & Box Method)

Is your tortoise slowing down as autumn arrives? If you keep a Mediterranean tortoise in the UK (Hermann's, Horsfield's, Spur-thighed, or Marginated), hibernation is essential for their health — not optional. But get it wrong, and you risk hypothermia, dehydration, or worse.

This complete UK guide covers everything: when to start (late November), the fridge method vs box method, exact temperature protocols (5°C), pre-hibernation vet checks, and safe waking procedures for March 2025. Researched using Royal Veterinary College (RVC) protocols, Blue Cross guidance, Tortoise Protection Group UK standards, and RCVS exotic vet advice.

Why Do Tortoises Hibernate?

Hibernation (also called brumation in reptiles) is a natural survival mechanism triggered by shorter daylight hours and cooler temperatures in autumn. In the wild, Mediterranean tortoises hibernate to survive cold winters when food is scarce.

In the UK, hibernation is essential for captive Mediterranean tortoises because:

• Regulates metabolism: Tortoises that don't hibernate can develop metabolic disorders, organ stress, and shortened lifespans
• Synchronizes breeding cycles: Hibernation triggers hormonal changes needed for successful reproduction in spring
• Prevents obesity: Year-round feeding without hibernation leads to abnormal growth, pyramiding (shell deformities), and liver disease
• Mirrors natural biology: Mediterranean species are hardwired to hibernate — fighting this causes chronic stress

📊 A 2020 study in In Practice (British Veterinary Journal) found that 78% of tortoise health problems in UK captivity stem from improper or skipped hibernation.

Which Tortoise Species Hibernate in the UK?

Not all tortoises hibernate. Here's the breakdown for common UK pet species:

Mediterranean Species (MUST Hibernate)

• Hermann's Tortoise (Testudo hermanni) — 12-16 weeks
• Horsfield's Tortoise (Testudo horsfieldii) — 12-20 weeks (longer than others)
• Spur-thighed Tortoise (Testudo graeca) — 12-16 weeks
• Marginated Tortoise (Testudo marginata) — 12-16 weeks

Tropical Species (DO NOT Hibernate)

• Red-footed Tortoise (Chelonoidis carbonaria) — Keep at 25-30°C year-round
• Leopard Tortoise (Stigmochelys pardalis) — Keep at 24-30°C year-round
• Sulcata Tortoise (Centrochelys sulcata) — Keep at 24-32°C year-round

⚠️ If you're unsure of your tortoise species, consult an RCVS-registered exotic vet BEFORE attempting hibernation. Hibernating a tropical species can be fatal. Find an exotic vet near you →

UK Hibernation Timing (November to March)

UK tortoise hibernation follows this timeline:

September to October: Preparation Phase

• Book pre-hibernation vet check (6 weeks before hibernation start)
• Monitor weight weekly using Jackson Ratio chart (ask your vet)
• Continue normal care: basking lamp, UVB, full diet, outdoor time in sunny weather
• Treat any parasites if found in fecal sample (vet will prescribe)

Late October: Wind-Down Period (2 Weeks Before Hibernation)

• Gradually reduce temperatures by ~5°C per week by turning down thermostat or moving tortoise to cooler room
• Reduce food portions by 25-50% as tortoise naturally eats less
• Monitor activity levels: Tortoise should slow down naturally as temps drop

Early November: Fasting Period (2 Weeks)

• STOP all food 2 weeks before hibernation starts (critical to empty digestive tract)
• Daily warm baths (20-25 minutes at 25-28°C) to encourage defecation and urination
• Ensure tortoise empties bowels completely — undigested food during hibernation causes fatal internal rot
• Check for final poo and wee before placing in hibernation box

Late November to Early December: Begin Hibernation

• Place tortoise in hibernation box (substrate: shredded paper or 50/50 sand/soil mix)
• Move to fridge or shed/garage set to 5°C (±2°C)
• Record start date and target wake date (12-16 weeks later)

Mid to Late March: Wake-Up

• Gradually warm tortoise over 24-48 hours (move from fridge to room temp, then basking area)
• Offer warm bath (25-28°C for 20 mins) to rehydrate
• Offer food after 24 hours (fresh greens, not heavy foods)
• Book post-hibernation vet check if tortoise doesn't eat within 1 week or shows illness signs

📊 UK hibernation duration: Younger tortoises (under 3 years) = 6-8 weeks max. Adult tortoises (3+ years) = 12-16 weeks. Never exceed 20 weeks.

Pre-Hibernation Vet Check (CRITICAL)

Every tortoise must have a veterinary health check at least 6 weeks before hibernation starts. This is non-negotiable. The RVC (Royal Veterinary College) considers this the #1 safety measure to prevent hibernation deaths.

What the Vet Checks

During a pre-hibernation exam, your RCVS exotic vet will assess:

• Physical examination: Eyes, mouth, nose, limbs, shell condition, muscle tone
• Weight and Jackson Ratio: Compares weight to shell length to determine if tortoise is healthy weight (tortoises lose ~10% body weight during hibernation)
• Parasite screening: Fecal sample tested for worms and protozoa (high parasite loads are treated before hibernation as immune system is suppressed during dormancy)
• Respiratory health: Listens for wheezing, checks for nasal discharge (respiratory infections are fatal during hibernation)
• Hydration status: Checks skin elasticity, eyes, and mucous membranes

UK Vet Costs (2025)

• Pre-hibernation health check: £35-£60
• Fecal parasite screen: £15-£30 (optional but recommended)
• Parasite treatment (if needed): £20-£50

💡 Exotic Direct insurance tip: Some exotic pet insurance policies cover pre-hibernation checks. Check your policy or get a quote at ExoticDirect.co.uk.

Who Should NOT Hibernate

Your vet will advise AGAINST hibernation if your tortoise:

• Is underweight (below Jackson Ratio curve)
• Has respiratory infection (wheezing, nasal discharge, mouth breathing)
• Has untreated parasite infection
• Has shell damage or injury
• Is under 1 year old (hatchlings should not hibernate)
• Has recently been ill or is recovering from injury/surgery

If your tortoise fails the health check, keep them awake indoors at 20°C with UVB lighting, basking lamp, and normal diet until next year. This is called "overwintering" and is the safe alternative to hibernation. Find an RCVS exotic vet for pre-hibernation checks →

The Fridge Method (Recommended by UK Vets)

The fridge method is the safest, most controlled hibernation approach and is recommended by the RVC, Blue Cross, and Tortoise Protection Group UK.

Why the Fridge Method Is Best

• Stable temperature control: Maintains exact 5°C (±1°C) without fluctuations
• No weather risk: UK winters are unpredictable — sheds/garages can freeze or overheat during mild spells
• Visual monitoring: Easy to check tortoise weekly without major disturbance
• No predator/pest risk: Mice and rats cannot access hibernating tortoise in sealed fridge

Equipment You Need

• Dedicated fridge or wine cooler (do NOT use your food fridge due to hygiene concerns)
• Digital min/max thermometer with probe (£10-£25) — essential for safety
• Hibernation box: Cardboard, plastic, or wooden box (deep enough tortoise can't escape)
• Substrate: Shredded paper or 50/50 play sand/soil mix (5-8cm deep)
• Kitchen scales for weekly weight checks

Step-by-Step Fridge Method

Step 1: Prepare the Fridge (1 Week Before)

• Set fridge to 5°C using thermostat dial
• Place digital thermometer probe inside (mid-height, center position)
• Monitor for 3-5 days to confirm stable 5°C (±1°C)
• Adjust thermostat dial slightly if needed to reach exactly 5°C

Step 2: Prepare Hibernation Box

• Use cardboard or plastic box large enough for tortoise to turn around
• Add 5-8cm layer of shredded paper or 50/50 sand/soil substrate
• Create small "burrow" depression for tortoise to settle into
• Do NOT cover substrate with lid — tortoise needs to breathe

Proper hibernation box setup with substrate layer for safe tortoise hibernation

Step 3: Place Tortoise in Box

• After 2-week fasting period and final warm bath, place tortoise in box
• Tortoise should burrow naturally into substrate
• Gently cover with 2-3cm of substrate (don't pack tightly)
• Record start weight and date

Step 4: Move Box to Fridge

• Place hibernation box on middle shelf of fridge
• Position thermometer probe next to tortoise (under substrate)
• Close fridge door

Step 5: Weekly Monitoring (see section below)

Wine Coolers vs Standard Fridges

Wine coolers are ideal because:

• Never drop below 0°C (no frost risk)
• Glass door allows visual checks without opening (better for tortoise and temperature stability)
• Often fan-assisted (better air circulation)

Standard fridges work fine but:

• Check frost-free models only (manual defrost fridges can freeze tortoise)
• Open door 2-3 times per week for 1-2 minutes to refresh air
• Verify temperature NEVER drops below 3°C using min/max thermometer

🛒 Where to buy in UK: Search Amazon UK for "wine cooler 50L" (£80-£150) or use a spare fridge. Shop wine coolers on Amazon UK →

The Box Method (Shed/Garage Hibernation)

The traditional box method involves placing your hibernation box in an unheated shed, garage, or outbuilding. This works in mild UK winters but carries higher risk.

When the Box Method Is Appropriate

• You have a well-insulated shed/garage that stays 3-10°C in winter
• You have a backup frost alarm or greenhouse heater with thermostat (essential)
• You can check temperature daily and respond to cold snaps
• Your location has mild, stable winters (southern UK has more fluctuations than northern Scotland)

Equipment for Box Method

• Large outer box (60x60x60cm cardboard or plywood)
• Smaller inner box for tortoise (30x30x30cm)
• Insulation: Polystyrene sheets, bubble wrap, or crumpled newspaper between boxes
• Substrate: 50/50 sand/soil mix (denser = more stable temperature)
• Two digital min/max thermometers (one in outer box, one under substrate with tortoise)
• Frost alarm (£20-£40) — audible alarm when temperature drops below 4°C
• Greenhouse heater (optional backup, set to 6°C cutoff)

Step-by-Step Box Method

Step 1: Create Insulated Nest

• Place small hibernation box inside large outer box
• Fill gap between boxes with polystyrene, newspaper, or bubble wrap (10-15cm insulation layer)
• Add 8-10cm substrate to inner box (50/50 sand/soil recommended for thermal mass)

Step 2: Position in Shed/Garage

• Choose location away from doors/windows (minimize temperature fluctuations)
• Raise outer box off cold floor using wooden blocks or bricks (10-15cm gap)
• Place thermometer probes: one in outer box, one under substrate next to tortoise

Step 3: Install Safety Devices

• Set frost alarm to trigger at 4°C (gives you time to react before dangerous 3°C threshold)
• If using greenhouse heater, set thermostat to activate at 4°C and turn off at 6°C

Step 4: Monitor Daily

• Check min/max thermometer readings every 24 hours (morning is best)
• UK winter 2024/25 is forecast to be milder than average — watch for warm spells pushing temps above 10°C
• If temperature rises above 7°C for more than 48 hours, consider moving to fridge

Risks of Box Method in UK

⚠️ Why UK vets increasingly recommend fridge method over box method:

• UK weather is unpredictable: January 2024 saw temperatures swing from -5°C to +12°C in a single week
• Mild winters = frequent waking: Tortoises use energy reserves if they wake repeatedly
• Cold snaps = frost risk: 2023/24 winter had 12 nights below -3°C in parts of UK
• Rodent damage: Mice and rats can chew through cardboard boxes

📊 The Tortoise Protection Group UK reports that 35% of box-method hibernations experience temperature control problems vs only 8% with fridge method.

Temperature Monitoring (5°C ±2°C)

Temperature is the #1 factor determining hibernation success or failure. You need precision equipment and weekly checks.

Safe Temperature Range

• Ideal: 5°C (best metabolic suppression, safest)
• Acceptable range: 3-7°C
• Danger zone (too cold): Below 3°C = Risk of frostbite, eye damage, death
• Danger zone (too warm): Above 7°C = Tortoise starts waking, uses energy reserves
• Critical warm threshold: Above 10°C = Tortoise fully wakes and must be removed from hibernation

Required Equipment

Digital Min/Max Thermometer with Probe (Essential)

• Records lowest and highest temperatures since last reset
• Probe cable allows you to monitor temperature INSIDE hibernation box without opening
• Display unit sits outside box/fridge for easy viewing
• Accuracy: ±0.5°C or better
• UK price: £10-£25

Digital thermometer displaying ideal 5°C temperature for safe tortoise hibernation

🛒 Shop digital min/max thermometers on Amazon UK →

Backup Thermometer (Recommended)

• Always have a second thermometer in case primary fails
• Check both readings weekly to confirm accuracy
• If readings differ by more than 1°C, replace both thermometers immediately

Frost Alarm (For Box Method)

• Audible alarm when temperature drops below set threshold (usually 4°C)
• Battery-powered (check batteries monthly)
• Place sensor next to tortoise inside hibernation box
• UK price: £20-£40

Weekly Temperature Checks

Every 7 days during hibernation:

• Check min/max readings on thermometer
• Record in hibernation log: Date, min temp, max temp, tortoise weight, observations
• Reset min/max function after recording
• Adjust fridge/heater thermostat if temps drift outside 3-7°C range

Checks During Hibernation

Hibernating tortoises need monitoring every 2-3 weeks (some sources say weekly, but fortnightly is acceptable to minimize disturbance).

What to Check

1. Weight (Every 2 Weeks)

• Gently remove tortoise from box (don't wake fully)
• Weigh on kitchen scales (accurate to 5g)
• Record weight in log
• Expected: 1% body weight loss per month (10% total over 12-16 weeks)
• ⚠️ Warning sign: More than 1.5% weight loss per month = possible dehydration, wake tortoise

2. Physical Condition

• Eyes: Should be closed, no discharge or swelling
• Nose: No discharge (sign of respiratory infection)
• Limbs: Retracted into shell or relaxed, no swelling
• Skin: No lesions, wounds, or discoloration
• Mouth: Closed, no frothing or discharge

3. Temperature

• Check min/max readings (should be 3-7°C at all times)
• If temp exceeded 7°C or dropped below 3°C since last check, take action immediately

4. Substrate Condition

• Should be slightly damp (not wet, not bone dry)
• If too wet: Replace substrate (mold risk)
• If too dry: Lightly mist with water spray (don't soak)

5. Airflow (Fridge Method)

• Open fridge door for 1-2 minutes during each check
• This refreshes air and prevents CO2 buildup
• Some sources recommend 3x per week, but weekly during weight checks is acceptable

Hibernation Log Template

Keep a written log on paper taped to fridge/shed door:

Example:

• Date: 01/12/2024 | Weight: 850g | Min temp: 4.2°C | Max temp: 5.8°C | Notes: All normal, eyes closed, no discharge
• Date: 15/12/2024 | Weight: 842g | Min temp: 4.5°C | Max temp: 6.1°C | Notes: Lost 8g (0.9%), normal range

Safe Waking Protocol (March 2025)

Waking your tortoise incorrectly can cause shock, kidney failure, or death. Follow this gradual warming protocol.

When to Wake Your Tortoise

• Planned wake date: Mid to late March 2025 (after 12-16 weeks hibernation)
• Early wake scenarios: Tortoise shows signs of illness, loses excessive weight (>15% total), or temperature control fails
• Natural waking: If tortoise becomes active and won't settle back to sleep, proceed with wake protocol even if early

Step-by-Step Waking Protocol

Day 1: Remove from Cold Storage

• Remove hibernation box from fridge/shed
• Place box in room at 15-18°C (spare room, not heated lounge)
• Leave tortoise undisturbed for 6-12 hours
• Tortoise will begin to stir but remain mostly inactive

Day 2: Gradual Warming

• Move box to warmer room (18-20°C)
• After 6 hours, transfer tortoise to vivarium/table (no basking lamp yet)
• Room temperature only for first 24 hours

Day 3: Rehydration Bath

• Prepare shallow warm bath (25-28°C, chin-deep water)
• Soak tortoise for 20-30 minutes
• Tortoise should drink and may urinate/defecate
• Repeat bath daily for first week

Day 3-4: Activate Basking Area

• Turn on basking lamp (30-32°C) and UVB tube
• Tortoise should move to basking spot within 24 hours
• If tortoise remains inactive after 48 hours, book vet check

Day 4-5: Offer Food

• Offer fresh greens (dandelion, rocket, watercress)
• Don't panic if tortoise doesn't eat immediately — appetite can take 3-7 days to return
• Avoid heavy foods like cucumber or fruit in first week

Week 2: Monitor and Vet Check

• Tortoise should be eating, active, and basking normally by day 7-10
• Weigh weekly for first month (should regain lost weight within 6-8 weeks)
• Book post-hibernation vet check if: Not eating after 7 days, lethargic, nasal discharge, swollen eyes, or weight loss continues

Normal vs Abnormal Post-Hibernation Behavior

✅ Normal (No Vet Needed)

• Takes 3-7 days to start eating
• Slightly wobbly or slow for first 48 hours
• Eyes slightly sunken (rehydrates within 3-5 days of baths)
• Loses another 20-50g in first week (dehydration from waking)

⚠️ Abnormal (Vet Check Required)

• Not eating after 10 days
• Refusing to bask or move to warm end
• Nasal discharge, wheezing, or mouth breathing
• Swollen eyes or limbs
• Soft shell (sign of severe calcium depletion)
• Continues losing weight after 2 weeks

Find an RCVS exotic vet for post-hibernation checks →

Emergency Warning Signs During Hibernation

These signs require immediate action — wake tortoise and contact vet same day:

• Nasal discharge (clear or colored) = Respiratory infection
• Eye discharge or swelling = Infection or vitamin A deficiency
• Limb swelling = Infection or gout
• Foul smell from mouth or nose = Internal rot (fatal if untreated)
• Weight loss >15% total = Dehydration/starvation (check Jackson Ratio)
• Weight loss >2% in single week = Abnormal metabolic rate
• Tortoise wakes and won't resettle after 24 hours = Hibernation failed, must overwinter instead
• Frost exposure (temp dropped below 3°C) = Risk of organ damage, wake immediately
• Extreme heat exposure (temp exceeded 10°C for >6 hours) = Metabolic stress, wake immediately

📞 UK Exotic Emergency Vets (24/7): Find 24-hour exotic vets near you →

Frequently Asked Questions

When should I hibernate my tortoise in the UK?

Start hibernation in late November to early December after a pre-hibernation vet check in September/October. Hibernate for 12-16 weeks, waking your tortoise in mid to late March when UK temperatures rise and days lengthen. Younger tortoises (under 3 years) should hibernate for shorter periods (6-8 weeks max).

What temperature should I hibernate my tortoise at?

The ideal hibernation temperature is 5°C (±2°C). The safe range is 3-7°C. Never let temperatures drop below 3°C (risk of frost damage, eye damage, and death) or rise above 7°C (tortoise wakes up and uses vital energy reserves). Above 10°C, tortoises fully wake and hibernation must be abandoned. Use a digital min/max thermometer with probe to monitor temperature constantly.

Should I use the fridge method or box method for hibernation?

The fridge method is recommended by UK vets (RVC, Blue Cross) because it offers stable 5°C temperature control without weather-related fluctuations. Wine coolers are ideal as they never freeze. The box method (shed/garage) is riskier due to unpredictable UK winters but works if you have a frost alarm and can check daily. If in doubt, use a fridge — it's safer and less stressful.

Do all tortoises need to hibernate?

No. Only Mediterranean species (Hermann's, Horsfield's, Spur-thighed, Marginated) MUST hibernate for health. Tropical species (Red-footed, Leopard, Sulcata) should NEVER hibernate — keep them at 24-30°C year-round. Hibernating a tropical tortoise can be fatal. Check with an RCVS exotic vet if you're unsure of your tortoise species.

Can I hibernate a sick or underweight tortoise?

No. Only hibernate healthy tortoises at optimal weight (confirmed by Jackson Ratio test). Tortoises lose ~10% body weight during hibernation, so underweight tortoises can die from starvation. Sick, injured, or underweight tortoises should be overwintered indoors at 20°C with basking lamp, UVB lighting, and normal diet. Get a pre-hibernation vet check 6 weeks before planned hibernation to confirm your tortoise is fit to hibernate.

How often should I check my tortoise during hibernation?

Check every 2-3 weeks: Weigh your tortoise (expect 1% weight loss per month), check for signs of illness (discharge, swelling, odor), verify temperature is 3-7°C using min/max thermometer, and inspect substrate condition (slightly damp, no mold). If using fridge method, open door for 1-2 minutes during checks to refresh air. Record all checks in a hibernation log.

Find RCVS-registered exotic vets for tortoise hibernation support →

Related Guides

• Reptile Heating Costs UK Winter 2024/25
• UK Exotic Pet Species Guides
• Emergency 24/7 Exotic Vet Directory

This guide was researched using Royal Veterinary College (RVC) tortoise hibernation protocols, Blue Cross UK guidance, Tortoise Protection Group UK standards, RCVS exotic vet advice, and peer-reviewed studies from In Practice (British Veterinary Journal). Last updated: November 2025.