The lethal heat dose for 50% primary human fibroblast cell death is 48 °C

Understanding the effect of heat on skin cells is important for the prevention of burn injury. Knowledge of the heat dose required to kill cells can be used to study the cellular mechanisms involved in thermal injury cell death, to assist with the development of novel burn treatments. In this study, primary human skin dermal fibroblasts were exposed to temperatures from 37 to 54 °C for 1 h and the relative cell viability of heat-treated and control cells was assessed. Cell damage and viability were assessed by light microscopy, MTT assay and live/dead staining. The LD50 for 1 h of heat exposure was 48 °C for primary fibroblasts; and there was evidence that thermal damage to cells begins to occur at 43 °C. This study presents a reproducible method for examining the effect of heat on primary human cells grown in culture on a cellular level and can be used in the future to study the mechanisms behind heat-induced cell death, to inform burn injury prevention efforts and effective post-burn treatment.