Performance and Thermal Perceptions of Runners Competing in the London Marathon: Impact of Environmental Conditions.The 2018 Virgin Money London Marathon (2018 VMLM) was the hottest in the race's 37-year history.  The aims of this research were to (1) survey novice mass participation marathoners to examine the perceptual thermal demands of this extreme weather event and (2) investigate the effect of the air temperature on finish times.  Of the surveyed participants, 23% classified their thermal sensation as 'warm', 'hot' or 'very hot' and 68% 'thermally comfortable' during training, compared with a peak of 95% feeling 'warm', 'hot' or 'very hot' and 77% 'uncomfortable' or 'very uncomfortable' during the 2018VMLM. 
THERM