I have this red patch on the left side of neck 2 inches under jaw line. does not itch, hurt or burn. weather has been humid. could it be heat rash?

Rash: Usually, heat rash looks like little bumps or pimples. This could be a fungal infection - usually a red blotch that is scaly. Or it could be impetigo, a patch that often has a honey colored crust. Fungal skin infections are treated with topical antifungal creams like clotrimazole. Impetigo, a staph skin infection is treated with antibiotics.