Goosebumps are actually left over from when humans were covered in hair. Goosebumps are activated in the cold because it would make the hair stand up, trapping air between the hair and creating a layer of insulation. They also pop up when you're scared because it would make the hair stand up and make you look bigger, which would scare the predator off (most of the time).
As humans started living in caves, using tools, and using fire (and of course, as the climate got hotter), we no longer needed the hair we that we needed during the karoo ice age and natural selection disposed of it accordingly. Of course, we still have hair, majorly around our genitals because it created protection from sticks, branches, thorn bushes ect.. any human without pubic hair 100,000 years ago would have had big problems with their goodies when running through the woods with spears to kill a dear, which would have meant they wouldn't reproduce.
Anyone still deny evolution and natural selection??