Dart frogs are very sensitive to temperature changes. They can tolerate a short term temperature fluctuation between 65 - 80 degrees, but for most dart frogs, the ideal temperature range is between 70-74 degrees. This ideal range is where these animals thrive the best!
Keeping dart frogs during the winter can pose a problem when the ambient temperature in our homes begins to lower but our frog’s needs are the same. Exposure to temperatures below 65 or above 80 can be extremely detrimental to the animal’s health.
*** The best way we have found to ensure the animals are always within an acceptable range is to keep the ambient room temperature in that range. Before investing in heating equipment, I urge you to consider keeping the ambient room temperature between 70-74 rather than investing in heating equipment.
One of the safest ways we have found to keep your vivarium within that ideal range of 70-74 is by using a heat mat in conjunction with a thermostat. The combination is very important. The heat mat alone has the potential of overheating the vivarium to above 80 degrees. So using a thermostat to regulate the mat’s activities is very important. This also means that during the fall and spring when the seasons are changing, the heat mat will only run when it is needed.
Choosing the heat mat size to use can be challenging. I usually suggest to cover 1/3rd of the back of the vivarium with heat mat . This should be enough to keep the vivarium a few degrees warmer than the ambient room temperature. If your ambient room temperature is low 60’s or 50’s, you may be better off considering moving the vivarium to a new location where the ambient temperature is warmer.
The most effective position for the heat mat is on the back or sides of the vivarium. The location you choose for the mat should be clear of any obstructions such as backgrounds and substrates. Ensure to follow all manufacturer instructions and precautions.
Once the mat is in place, it’s time to install the thermostat . These will come with a main unit where your heat mat plugs into and a probe that extends from the main unit into your vivarium. The probe should be placed mid height in your vivarium in an area that is exposed to the open air in the vivarium so that it can take proper readings. Ensure to follow all manufacturer instructions and precautions.
Now simply set your thermostat to the desired temperature and let it take it from there. If the desired temperature change is greater than 3 degrees, it may be best to change the temperature slowly. To do so, raise the thermostat 2 degrees every hour. It is best to closely monitor the temperature for the first few hours after installing and setting to the proper temperature. During the first few weeks, it is important to ensure your heating equipment is functioning as expected. Check your temperature every morning and night. After your equipment has been working for a few weeks, I suggest checking both temperature and humidity every time you feed.
http://www.reptilesmagazine.com/Ideal-Heating-For-Your-Reptiles/