You don't want to be on the day side of Mercury; 430 °C will not be very pleasant. Nor will you want to be on the dark night side with -170 °C. The closest planet to the Sun is a planet of extremes. Despite its closeness to the Sun and the extreme temperatures of 430 °C during the daytime, there are some areas on Mercury with permafrost! Craters close to the pole contain areas that are permanently dark and cold. Temperatures will never exceed -90°C in these places so that scientists have been able to discover about a trillion tons of water ice there.