Where to keep Guinea Pigs

Question
Hi,
I have my Guinea pigs outside at the moment in their hutch. I have covered it
over with bubble wrap, a quilt, and a groud sheet, though i do not think it will
keep them warm enough. I always give them hay everynight, but i still think
they are getting too cold. My dad thinks they are fine outside but i dont
beleive him. If you know the temperatures when to bring Guinea Pigs inside  -
e.g. when it gets below 5 degrees - could you help me please. Thanks in
advance.
Catherine xx

Answer
Hi!  Guinea pigs can successfully live comfortably outside, as much as i understand your fear about your pigs getting a bit cold (i have my pigs living inside as i too worry maybe a little too much over them!)
The most important points to bear in mind with cages both indoor and out is keeping them dry and draught-free.  Thoroughly cleaning the cage out every other day or so, and spot cleaning every day will ensure the cage is maintained dry and free of ammonia build up from stale urine.  Dampness from wet, old bedding, and even from the elements getting inside, can create an environment that can give small furries respiratory infections such as pneumonia, which is what you want to avoid.
Secondly, to ensure the cage is draught-free, make sure all the sides, cage doors etc are sturdy and tight-fitting.  Any loose joints in the wood edges or or around hinges and door frames of hutches can encourage cold air from outside to get in and give the cage an uncosy breeze.  This again contributes to the development of infections relating to the chest.  
I think you've got the cage pretty much covered, and i would say that you should only cover the cage right over only when the weather is really bad, and not on fine days, so a snowy day should still be okay for your pigs if the cage is snugly insulated for them, especially through the evenings.  (They don't want to be kept under darkness of a duvet all day long!)
Anyway, i hope this has eased your worry somewhat!  Any further questions, don't hesitate to ask.