Feeling Feverish And Chillness Of Bones

for a week am feeling like little weak, in the afternoon i feel chillness, like a very mild fever, pain in right upper back, and some times mild headache, today i started feeling mild pain in right side of my neck too, i experience this after exposed to a severe cold weather, i didnt wear my winter weather pant on that day, i felt the chillness in my bone. i went inside the warm up room. since then i experience this for a week, can you please guide me what would this be?