Introduction per se  1 2 3 7 8 10 11 13 14 1 2 3 15 22 Studies included in this review were identified by means of a comprehensive Medline search, limited to the English language literature, using the following keywords: 'dantrolene' and 'hyperthermia' or 'heat'. Each article identified was further examined for relevancy. Dantrolene 23 25 25 30 27 29 30 25 25 31 25 Heat stroke and 'thermic stress syndrome' 32 33 1 34 34 36 32 36 35 9 10 15 17 37 8 10 15 Dantrolene use in heat stroke 15 8 16 17 21 21 38 39 19 20 18 Discussion 17 40 41 42 43 44 45 31 17 19 1 46 15 17 17 15 21 47 48 31 49 50 2  49 51 54 20 Conclusion Therapy with the accepted MH prophylactic dose of 2–5 mg/kg resulted in a possible benefit from dantrolene treatment in HS in some studies, whereas in others it was not found to be effective. The limited literature does not support the routine use of dantrolene as an adjuvant cooling technique in the setting of HS. Nevertheless, because dantrolene does appear to increase cooling rate, furthur studies are advised for dantrolene use in severe cases or cases in which no improvement is observed with other cooling methods. Wider trials are still needed to evaluate the efficacy of dantrolene in reducing mortality, thereby justifying its use in HS. Noteworthy, dantrolene should not be used as a single cooling method, and its administration should only be in addition to the well established 'conventional methods'. Competing interests None declared. Abbreviations CHS = classic heat stroke; CNS = central nervous system; EHS = exertional heat stroke; HS = heat stroke; MH = malignant hyperthermia; NMS = neuroleptic malignant syndrome.