Hi Julian,
Welcome to HCM,
Goose bumps or goose skin whatever you call it is a reaction of the body to environment.
It is the contraction of very small muscles the numerous Erector pili mucles which are there in the skin particularly around the hair follicles.
The change in environment can be anything
cold, warmth, blowing of air, touch, sudden sound, threats, fear, rage all of them are well known causes.
Sensitivity of every individual is different. Some like you get goose
pimples by slightest impulse and others would withstand strong cold weather.
You can try heavy exercises and
yoga to bring down your sensitivity but no drugs are effective.
I hope you would find it helpful.