Including point heat sources in a 2D transient PDE heat equation

I want to be sure that I included the point heat sources correctly in my PDE.
The result should be:
enter image description here

I wrote:

q0 = 1;
Subscript(Q, 0) = 
  q0*(DiracDelta(x - x1)*DiracDelta(y - y1) + 
     DiracDelta(x - x1)*DiracDelta(y - y2)*DiracDelta(x - x2)*
      DiracDelta(y - y1) + DiracDelta(x - x2)*DiracDelta(y - y2));
heqn1 = Subscript(k, 
    CLS)*(D(Subscript(T, D)(x, y, t), x, x) + 
      D(Subscript(T, D)(x, y, t), y, y)) + Subscript(Q, 0) == 
  Subscript((Rho), CLS)*Subscript(Cp, CLS)*
   D(Subscript(T, D)(x, y, t), t)

I haven’t considered the time-dependency for the heat source just yet to simplify the notation.
Thank you in advance!