thermodynamics - How to define heat and work?

In textbooks, heat is usually defined as the energy transfer due to temperature difference.

However, we don't know what temperature is in the first place. I think it's better to define heat first and then define temperature $1/T$ as the integrating factor so that one has $$\oint\frac{\delta Q}{T}=0$$ and hence define entropy as the potential $$\Delta S=\int\frac{\delta Q}{T}$$

So my problem is I cannot use temperature or entropy when defining heat.

So what is the definition of heat?

I think my problem can be solved if one can define either heat or work without mentioning temperature and entropy. For instance, if we can somehow define work, then heat can be define as the energy change not in the form of work. And vice versa.

So in summary, my question is how to define work or heat without mentioning temperature and entropy in thermodynamics (without referring to statistical mechanics)?