It is permissible for you to use a tissue to stop a runny nose during prayer. The scholars stated that it is permissible to make some slight movements during prayer if the worshipper needs to do so.

Those who live close to the Arctic Circle, where they have continual night or continual day for several months, should look to the closest city to them where night and day are distinct in each twenty-four hour period, then they should do the five daily prayers based on the timing in that city.