The aim of the present study was to assess the immediate effects of upper thoracic manipulation on skin surface temperature in the region of the T3 vertebra and biceps brachii muscle in healthy women. It is a randomized controlled blind study. Twenty-six healthy women of the university community were randomly allocated to an experimental group (n = 13) and a placebo group (n = 13). A single session of the upper thoracic spine manipulation (segment T3)was performed. Infrared thermography was used to determine changes in skin surface temperature in the region of T3 and the biceps brachii muscle, which would indirectly reflect sympathetic activity. Images were taken prior to manipulation, immediately after and both five and 10 minutes after manipulation. Repeated measures ANOVA with the post hoc Bonferroni test and the independent samples t-test were used for the intragroup and intergroup comparisons, respectively, with the level of significance set to 5%.