Hello and welcome to FF! Please read this ASAP to learn about your frog needs:
Frog Forum - Pacman and Horned Frogs - Ceratophrys - Care and Breeding. Recommend to heat the air couple in. above substrate to 82F now. Low temps can kill your frog and even long exposure to mid 70sF can cause permanent damage to frog's kidneys and lymph hearts resulting in edema

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Heat mats are inefficient when used on sides (can't attach to enclosure bottom with frogs); so recommend use a dome with built-in dimmer (Flucker's or others) and a 60W Ceramic Heat Emitter. You can cover the whole screen top in aluminum foil, trace the dome with a Sharpie and cut around circle making it around an in. wider. That will help retain heat and humidity in. Hopee this helps and good luck

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