I have sever sinusitis problem. Using cold water creates headache that I cannot bare. Thus I always use hot water in winter for waduh and shower. However, when I am outside home, it is not possible always to manage hot water, specially when I am at office. Can I perform tayammum in this situation?

All perfect praise be to Allah, The Lord of the Worlds. I testify that there is none worthy of worship except Allah, and that Muhammad is His slave and Messenger.

If you are asking about only refraining from washing the nostrils, (known as Istinshaaq; sniffing water into the nasal cavity) and performing Tayammum (dry ablution) instead of it, and not about totally abandoning the use of water, then there is no harm on you for abandoning Istinshaaq in ablution as it is a recommended act (I.e., not obligatory) in ablution and Ghusl according to the view of the majority of the scholars. An-Nawawi said:

“Our view [i.e. the view of the Shaafi’i School] and the view of the majority of the scholars is that Istinshaaq is a recommended act in ablution and Ghusl.” [End of quote]

This is the view we adopt here in Islamweb.

If you are asking about not using water in all the limbs of ablution and not Istinshaaq only, then if you are certain or pedominantly believe that you will become sick if you use cold water, then if one fears harm by the use of water in ablution, it is permissible for him to perform Tayammum instead if it is not possible at all for him to use water.

Ibn Qudaamah said:

“If one fears severe cold but he can warm the water or can use it in a manner with which he is safe from harm, such as washing limb by limb, and whenever he washes one limb he covers it, then he is obliged to do so. However, if he is unable to do so, then, according to the view of most scholars, he may perform Tayammum and pray [..] the reason behind the statement of Ibn Mas’ood: “He may not peform Tayammum."; is due to his own explanation when he said: “If we give them concession about this (Tayammum), then whenever water becomes a little cold, they would leave it and peform Tayammum instead.” [End of quote]

For more benefit, please refer to Fataawa 288784, 366532, 285187, 82337, 85128 and 87006.

Allah knows best.