We were delighted to see a new study in 2020 specifically about canicross and the factors that affect a dog's body temperature.
Dogs overheating can be a serious issue so we are keen to share this new bit of research:
Investigating factors affecting the body temperature of dogs competing in cross country (canicross) races in the UK
AJ Carter, EJ Hall
You may also find this document which outlines ASSA's race rules useful when deciding whether it is too warm to run with your dog: