Wet vs dry
Choose the right clothing for the conditions. When it's cold but dry, using fleecy top clothing that's warm and breathable is best. When it's cold and wet, you need to keep that water out. Look for water-repellent rain jackets that don't hold or let in water.
Whatever the weather, you’re better safe than sorry. Taking that one extra jacket, even if it's a light wind jacket, is excellent security.
Riding in the heat
Riding in hot conditions is a little trickier to get right than riding in cold – mainly because you can only take off so many clothes to regulate your heat.
Once your core temperature goes past a certain level, your brain will choose survival over performance. Your output will start to decrease as your body redirects your blood to perform cooling duties.
With this in mind, there has been a lot research on what you can do to minimise the affect.
Heat adaptation
Spending a period of 10 to 14 days in hot environments sees a change in your blood plasma levels, which helps core temperature regulation.