Not every boot is for every foot, just like not every sneaker is for every foot. The boot tongue is designed to hold the foot securely in place as it distributes the pressure of flexing, to absorb shock of skiing and insulates the skier from pain. Shin Bite is a condition caused by friction of the skin or sock rubbing against the tongue of the boot. This can be a result of a bunched up sock or an improperly fit boot. Some of this pain can be relieved by adding a customized liner or readjusting your socks and bindings.
Feet usually become cold due to restrictive blood flow.
An improperly fitted boot will put uneven pressure on the foot, limiting blood flow. Again, proper fit is crucial. The result of this should be that when you are wearing a pair of properly fit ski boots your adventures on the slopes will be more comfortable and probably last longer than 2 runs per shot. This information has been provided for your convenience and please be aware that the people that work in your ski shops are usually highly educated and can be an asset for you.