The cold is often seen in a negative light and is equated with contraction and paralysis; while heat symbolizes something alive and generous. In reality, there are two types of heat and cold.
There is heat which dilates and brings life and maturity, and heat which burns and dries. There is the cold that preserves all that is good, and cold that paralyzes life.
Take for example the water cycle in nature. When exposed to the heat of the sun’s rays, water heats up and evaporates.
Once in the upper atmosphere, it cools down, crystallizes and falls back to the earth in the form of snow.
When the sun melts the snow, water runs down into the valleys where it joins the rivers, the lakes and the oceans.
It then evaporates and the cycle starts over again. This is how nature uses the alternation of heat and cold to sustain life.
As for humans, their intellect must be cold so they may think correctly and progress on the path of wisdom; while their heart must remain warm to express love.