Too low tempratures?

[SterlingAce]

Hi everybody I'm from South Africa and worried about our winter temperatures and hibernation.
It is not out of the ordinary if winter temps drop to 1'c,getting below 10'c inside the house. I have 3 tegus 2 reds and one b&w. Should I provide extra heat on a timer for them? Keep it on all the time? Put it on when the temps drop? We have lately had a bit of a cold spell with night temps reaching around 14'c inside. So far they seem ok with it. Their cage stays relatively stable concerning temp but my thermometer broke so I'm not exactly sure of the temps but it feels nice and warm.They are also still eating well. I'm going to get a new thermometer asap.
Are there any extra special precautions I need to take?

 

[chelvis]

I would watch if the temps get too low, anything below 10c can be harmful to tegus. That being said mine did survive two bone chilling nights at 1c but it would not be good to go much below that. As for hibernation I would keep the temps up in the day until the slow down and stop eating. If you turn off the heat on them too soon they can not properly digest what food is in there system.