Studies investigating hyperbaric oxygen treatment (HBOT) to improve outcome in burns have been inconclusive. In this study, we aimed to characterize early thermal burns injury in adult patients with < 40% total body surface area (TBSA) and to determine the effects of HBOT administered within 24 h to 48 h of a burn injury. Seventeen subjects were randomized into control (n = 9) and HBOT treatment (n = 8) arms. Burn depth, measured by laser Doppler imaging (LDI) and histologically, white blood cell (WBC) count and plasma cytokine inflammatory markers were assessed at 24 h (pre HBOT) and 48 h (post HBOT) post burn, as were immunohistochemistry and microbiology of burns tissue samples at 48 h post burn. WBC count and serum interleukin (IL)-1β, IL-4, IL-6, IL-10 and interferon-γ were significantly elevated 24 h after burn, but no significant changes in any of these parameters were found with HBOT. HBOT had no significant effect on burn depth. Two HBOT patients and four control patients developed positive bacterial cultures. Slower than anticipated recruitment resulted in considerably fewer patients than planned being studied. Inflammatory markers were significantly increased at 24 h in patients with < 40% TBSA burn. Early HBOT had no apparent effects on any of the parameters measured in this small pilot study. HBOT may possibly have a broad-spectrum antimicrobial effect worthy of further study. We report our methodology in detail as a possible model for future burns studies. Chong, Kan, Song, Soh, Lu, , , , (2013). Characterization of early thermal burns and the effects of hyperbaric oxygen treatment: a pilot study. Diving and hyperbaric medicine, 2013 Sep;43(3):157-61. https://www.ncbi.nlm.nih.gov/pubmed/24122191