Reptile thermostats
Use a dimming thermostat for heat sources that give off light (halogen and incandescent basking bulbs) and for deep heat projectors, so the lamp holds temperature without switching on and off. An on/off or pulse-proportional thermostat is fine for lightless heat: ceramic heat emitters, heat mats, heat tape and radiant heat panels.
Which thermostat does what
- Dimming Thermostatvariable voltage continuous heatUse for halogen and incandescent basking bulbs and deep heat projectors to prevent flashing and prolong bulb life. It also works with ceramic heat emitters.Amazon ↗
- Pulse-Proportional Thermostatrapid micro-bursts of powerUse for lightless heat like ceramic heat emitters, radiant heat panels and heat mats when you want very steady temperatures. Never use it on a bulb that gives off light.Amazon ↗
- On/Off Thermostatbinary power switching outputUse for heat mats, heat tape and ceramic heat emitters, where small temperature swings are fine. It also works as a high-limit safety cutoff on a second probe.Amazon ↗
Sizing: Choose a thermostat rated well above the total wattage of everything plugged into it. A 20% to 25% margin is a sensible minimum (for example, a 100-watt bulb needs a channel rated for at least 125 watts).
What each animal's guide calls for
From the checklists on each care guide, so this table and those pages always agree.
- Bearded dragonOn/Off Thermostat (Failsafe)105–115°F basking$35–$50
- Ball pythonDimming Thermostat88–92°F basking$45–$120
- Leopard geckoDimming Thermostat94–97°F basking$45–$90
- Corn snakeDimming Thermostat88–92°F basking$35–$80
- Hermit crabDigital Thermostat Controller78–85°F warm side$18–$30
- Crested geckoDimming Thermostat82–85°F basking$35–$75
- Russian tortoiseDimming Thermostat95–105°F basking$35–$70
- HedgehogDigital Temperature Thermostat76–80°F warm side$20–$40
- Blue-tongue skinkDimming Thermostat or Lamp Dimmer100–115°F basking$20–$75
- Sulcata tortoiseDigital Dimming Thermostat95–105°F basking$50–$140
- Pacman frogDimmer or Thermostat82–85°F basking$20–$40
- Green iguanaDimming Thermostat110–120°F basking$50–$140
- White's tree frogDimming Thermostat82–84°F basking$35–$80
- Emperor scorpionDigital thermostat controller78–82°F warm side$18–$35
- Boa constrictorProportional Dimming Thermostat86–90°F warm side$80–$220
- Gargoyle geckoDimming thermostat82–85°F basking$35–$75
- Argentine teguHigh-Wattage On/Off Thermostat (Failsafe)125–135°F basking$35–$100
- Hognose snakeDimming Thermostat90–95°F basking$40–$90
- KingsnakeDimming Thermostat85–90°F basking$35–$80
- Milk snakeDimming Thermostat85–90°F basking$35–$80
- African fat-tailed geckoDimming Thermostat90–94°F basking$35–$90
- UromastyxThermostat with Probe120–130°F basking$35–$60
How to choose
- 01Identify your primary heat source typeMatching the thermostat to the heater prevents bulb burnout, flashing light and unstable temperatures.
- 02Verify total wattage requirementsExceeding the maximum wattage of a thermostat channel can cause device failure or a fire.
- 03Secure the sensor probe at the basking spot or other area you are controllingA probe hanging in the air reads cooler than the basking surface, so the thermostat keeps heating and the surface can get hot enough to burn.
- 04Confirm high/low temperature alarms and safety shutoff featuresFail-safes help prevent fatal overheating if a heater or thermostat fails or a probe gets knocked loose.
Common mistakes
- Running a halogen basking bulb on an on/off thermostat as its main control, which makes the light switch on and off through the day and shortens bulb life.
- Dangling the temperature probe in mid-air instead of securing it to the surface, causing the thermostat to overheat the actual basking spot.
- Assuming the manual dial (rheostat) on a heat mat is a thermostat. It can't respond when the room temperature changes, so surfaces can overheat.
- Using a single thermostat channel to control multiple enclosures with different ambient conditions, risking hyperthermia in one unit.
Questions people ask
Why is a reptile thermostat essential rather than optional?
Heat lamps, mats and emitters with no control can heat surfaces well past 120°F, which causes burns and heatstroke. Reptiles depend on outside heat to set their body temperature, so a thermostat on every heat source is essential.
Where should I place the thermostat probe in a terrarium?
For an overhead lamp, secure the probe on the basking surface under the lamp, a little to the side so the animal doesn't lie on it. For a heat mat, place it on the enclosure floor directly above the mat. Always confirm surface temperatures with an infrared thermometer.
Can I use an on/off thermostat with a basking bulb?
Not as the main control. Some keepers pick a bulb wattage that gives the right basking temperature at full power, then add an on/off thermostat set a few degrees above that as a safety cutoff that rarely switches. For everyday control of a light-emitting bulb, a dimming thermostat is the usual choice.
Can I plug a power strip with multiple heat lamps into one thermostat?
Only if they heat the same enclosure and their combined wattage is under the thermostat's rating. For separate zones or enclosures, use a multi-channel thermostat with a probe for each.
What happens if a thermostat probe gets wet or covered by substrate?
A wet or buried probe usually reads cooler than the real surface, so the thermostat pumps more power into the heater. Secure probes with clips or suction cups away from water dishes and digging areas.