Investigation of the Effects of Rapid Heat Acquisition and Desloratadine on Hematological Profiles of Firefighters




King, Robert

Journal Title

Journal ISSN

Volume Title



PURPOSE: To evaluate the impact of rapid exertional heat stress (EHS) on SFF’s WBC and platelet (PLT) count, and whether desloratadine influences the hematological response. METHODS: In two sessions, five male SFFs (Age: 31.6 +/- 6.44 yrs; Height: 1.91 +/- 0.06 m; Weight 94.83 +/- 12.53 kg; VO2max: 49.96 +/- 6.52 ml/kg/min) walked on a treadmill in structural firefighting PPE at 3.0 mph with a 5% incline until reaching volitional maximum or a core temperature (Tc) of 39.5 C. Participants ingested 10mg drug/placebo and a Tc capsule 2 hours prior, with an identical drug/placebo dose 24 hours later. Venous blood samples were obtained immediately before, after, and 2-, 24-, 48-, and 72-hours post-heating. RESULTS: Tc increased by a mean of 1.89 +/- 0.44 C during EHS. No significant differences between drug and placebo were observed for WBC; PLT; and number of LY, MO, NE, EO, and BA (p>0.05). All variables showed significant differences over time following EHS (p<0.05). Significant elevations in WBC, PLT, LY, & NE were found between baseline and either immediately or 2 hours post testing (p<0.05). CONCLUSION: EHS significantly impacts WBC markers and PLT counts within 72 hours post exposure. Desloratadine does not appear to influence these hematological responses.



antihistamine, heat stress, hematology, structural fire fighter