( ( ( Blood flow ) ( to ( the skin ) ) ) ( ( ( increases , ) ( ( causing ( blood flow ) ) ( to ( decrease ( to ( the ( vital organs ) ) ) ) ) ) ) . ) )
(ROOT (S (NP (NP (NN Blood) (NN flow)) (PP (TO to) (NP (DT the) (NN skin)))) (VP (VBZ increases) (, ,) (S (VP (VBG causing) (NP (NN blood) (NN flow)) (S (VP (TO to) (VP (VB decrease) (PP (TO to) (NP (DT the) (JJ vital) (NNS organs))))))))) (. .)))
Blood flow to the skin increases, causing blood flow to decrease to the vital organs.
(ROOT (S (NP (NNP Blood)) (VP (VBP flow) (VP (VB decrease) (SBAR (WHADVP (WRB when)) (S (NP (NN blood) (NNS vessels)) (VP (VBP constrict)))))) (. .)))