We have got around 0F for 2 nights now and they are just fine - no heat, no insulation. At 9 months yours are better insulated that hours 2y old because some of them still molting.Below 0 and 9 months
Also if you supplement heat at night they may decide that it is not warm enough outside during the day to go out.
 
	 
 
		 
 
		 
			
		
		
		
	
	
			
		 
			
		
		
		
	
	
			
		 
			
		
		
		
	
	
			
		 
 
		 
 
		 
 
		 
 
		 
 
		
 
 
		 
 
		 
 
		 
 
		 
 
		 
 
		 
 
		 
 
		 
 
		 
 
		 
 
		 
 
		