Correct

热源

/ rèyuán / 
Strokes

Definition

heat source

Example

As a Noun

heat source

1
Qǐng
请
yuǎnlí
远离
rèyuán
热源
  
。

Keep off/away from heat source.

2
Méiqìguàn
煤气罐
fàngzài
放在
rèyuán
热源
fùjìn
附近
hěn
很
wēixiǎn
危险
  
。

It is dangerous to leave a gas cylinder near the source of heat.