If your guinea pigs are outdoors over the autumn and winter, you need to do all you can to keep them warm enough.
Guinea pigs are similar to humans when it comes to the temperatures at which they feel most comfortable. Therefore you can imagine if you were in an outdoor environment with nowhere for warmth how cold you'd feel. In fact, your pets may need to be brought inside for the very cold weather.
If they are outside and it is a little chilly, they would benefit from the warmth of a heat pad.
Snugglesafe Microwaveable Heatpads are specially made for pets and are recommended by vets and used by pet boarding facilities and rescue shelters.
These soft fleece covered pads gives up to 10 hours warmth so will give them comfort on chilly nights or days.
Pop it in the sleeping compartment of their hutch and cover with loads of hay. Your guinea pigs can then burrow into the hay which will give them a lovely warm snuggly place to sleep.
For extra warmth, you could try putting a pigloo on top of the heatpad and filling the pigloo with hay. This should keep the warmth in even more.
Find out more about how to keep outdoor guinea pigs safe from the cold and other weather here...