Do Chihuahua Get Cold Easy What Is A Good Weather Temperature For A Toy Chihuahua To Be Out In?

Chihuahua's are known to suffer from hypothermia. Some long haired chi's are okay in colder weather but a smooth coat definatly needs clothing of some sort:
I.e.
Summer : Vest
Winter: Thick Jumper / puffa jacket (& Booties)
autumn: Light fleece jacket or (& optional scarf / booties)
Spring: Depending on weather vest to light warm top.

Also don't let them wear pj's or anything to bed as this will cause them to become unable to cope with outdoor weather and may become over-heated resulting in possible fits. These clothing suggestions are made for 9mth - adult chi's in britain; for babies or teacups they will probably needed a light fleece jacket or jumper when going out in any weather.

They get cold very easily, there isn't much to them.  I have had them for over fifty years.  Make sure they have warm coats, you can buy socks, boots, hats for them, wrap them in a blanket and carry them where they need to go.  Their feet will freeze very quickly as there is very little blood supply to that area.

100 Fahrenheit