@MagNeto 

It depends where you've placed the device.

In general, it should be positioned in a well ventilated place on a firm surface.

If you believe it's getting too hot, you can put some spacers underneath or fix it vertically with the help of the two holes on the bottom:

@Magneto olha qual padrão de segurança está no wifi,se é o wpa 2/wpa3 ou wpa/wpa 2.

O wpa2/3 está fazendo o roteador aquece mesmo,como tbm está limitando a banda de 5ghz

@terziyski 

My router is placed in a well ventilated space and also the router is placed on a sleeper to get better air circulation in the under surface...i checked the temperature of the under surface and it showing 43°c ( ambient temperature is 29°c).is this a software issue or is normal?

@Esmy my wifi  password setting is wpa/wpa2 with aes

@MagNeto 

If your router is working as it should then that's normal.

Sometimes to lower the working temperature if device behaves abnormal, I've seen a suggestions to lower the wireless radio transmission power from high to medium.

@terziyski as of now router is working perfectly fine but i am afraid of long term issue which may occur with the router because of such high temperature.

@terziyski can you check your router temperature?

@MagNeto 

I would leave it as it is. I believe that's normal for this time of the year - all my devices experiencing higher temperatures during summer season.

My router is two floors above and I don't have an IR thermometer, but on touch it feels warm - that's normal.

Your highest ambient temperature for using the device is 40℃.