Changes

*[[Erector Muscle|Erector muscles]] contract causing body hairs to stand on end. This creates a pocket of trapped air under the hairs which insulates the body.

*[[Blood Vessel|Blood vessels]] near the surface of the [[skin]] [[Vasoconstriction|constrict]] reducing [[blood]] flow close to the [[skin]] preventing [[Thermal Energy Store|thermal energy]] being lost to the [[skin]].

===References===

:[https://www.amazon.co.uk/gp/product/0008158754/ref=as_li_tl?ie=UTF8&camp=1634&creative=6738&creativeASIN=0008158754&linkCode=as2&tag=nrjc-21&linkId=27ad53b0283feeff7fc5ae04a9e205f511 ''Skin, pages 106-7, 148, 189, GCSE Biology; Student Book, Collins, AQA '']

:[https://www.amazon.co.uk/gp/product/1471851338/ref=as_li_tl?ie=UTF8&camp=1634&creative=6738&creativeASIN=1471851338&linkCode=as2&tag=nrjc-21&linkId=425855d5890466e47189e1c21b67a1ea ''Skin, pages 85-6, GCSE Biology, Hodder, AQA '']