toplina

1. warmth; heat
   Volim toplinu kamina zimi. — I love the warmth of the fireplace in winter.
   Ova jakna dobro čuva toplinu. — This jacket keeps the warmth in well.
2. (of feelings, manner) warmth; cordiality
   Dočekali su nas sa mnogo topline. — They welcomed us with great warmth.
   U njenom glasu se osećala toplina. — You could feel warmth in her voice.

In physics and technical contexts toplota is more usual.