from your symptoms i think you are suffering from allergic rhinitis
you seem to be allergic to dust and sudden change in temperature. it is very frequent in summer days since there is a lot of variation in temperature outside the room and inside the room.
i would suggest you to put on the fan and air conditioner not immediately once you return from a high temperature area, rather allow your body to adjust to the room temperature before you switch on any of these.
you can use a good quality mask for protection against dust, or cover your nose and mouth with thin cotton cloth.
antihistaminics once daily at a low does will definitely help to decrease your sneezing
do visit a doctor if symptom does not subside to get your sensitivity checking done.
take care and get well soon.