Instanteneous Jump of Temperature

Hi, COMSOL community.

I model the heating of solid (time dependent task). The heating is instaneous. I.e. heat spreads through the solid without any sources but in several (point-like) moments temperature jumps. The description of the heat source is possible only by these temperature jumps. The description by the common way - by the heat power density - is impossible due to physical limitations.
So, the scheme of the heating is:
1. Initial instanteneous temperature jump at t=0
2. Free heat spreading during the time from t=0 to t1
3. Instanteneous temperature jump at t=t1
4. Free heat spreading during the time from t=t1 to t2
and so on

So, the question is: how I can include temperature jumps into the model?
I could assume 2 possible ways:
- using separate steps (Step) for every time interval (0,t1), (t1,t2)
- or using several Heat Transfer in Solids Interfase (Physics) for every time interval (0,t1), (t1,t2)
where initial conditions for Step/Physics are results from previous Step/Physics.
If these are right assumptions, could anybody tell me the way to transfer the data from one Step/Physics to another?
Or, may be, there is any simple way?