Symbol 3652 from ISO 7000 - Title/Meaning: Protection against heat but not flame 
Function/description: On protective clothing: To indicate that the clothing or material provides protection against heat but not against flames.
Own work using: iso.org/obp/graphics/grs/36771b99-8f3f-4789-ba7b-a8e39cc1de3d 200.png
Vectorization:  Mrmw