Outdoors: some short haired dogs and senior dogs need help staying warm in the colder weather. Select and use good quality dog apparel. Some velcro edges can be sharp, check and trim.
RC Pet Products. Brand, ‘West Coast Rainwear’ — www.rcpets.com
Premier Pet. Brand, ‘Fido Fleece’ – www.fidofleece.com
Vibram. Brand, ‘My Good Dog’ — www.vibramk9.com
Indoors: try a good heating pad specially designed for pets.
Heating Pads for dogs (dog products, beds, varied)
Hound Warmer Deluxe (and much more)
OR search online for a Heated Travel Pad that plugs into car outlet or cig lighter. Alert, fabric can easily be damaged if a dog scratches to nest; please sew a sturdy bag to cover the pad. Dense polar fleece sewn in double thickness can be effective. Plus, later you can remove and wash the sewn cover.