Studies have shown that elite athletes such as tennis players can reach core temperatures as high as 40 degrees Celsius, associated with collapse from heat exhaustion.
Notes on verification
Corroborated by multiple independent sports-medicine sources (peer-reviewed reviews, UpToDate, ACSM position stand) confirming elite athletes including tennis players can reach core temps near or at 40°C, and that this range aligns with clinical definitions of heat exhaustion/heat stroke. Minor nuance that many athletes reach 40°C without symptoms doesn't contradict the claim's phrasing.
Sources
- Firefighters know how to look after themselves to prevent heat exhaustion - ABC News (abc.net.au)
- https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10588574/ (ncbi.nlm.nih.gov)
- https://pubmed.ncbi.nlm.nih.gov/17473783/ (pubmed.ncbi.nlm.nih.gov)
- https://www.uptodate.com/contents/exertional-heat-illness-in-adolescents-and-adults-epidemiology-thermoregulation-risk-factors-and-diagnosis/print (uptodate.com)
- https://www.laykold.com/news/tennis-feels-the-heat (laykold.com)
- https://pmc.ncbi.nlm.nih.gov/articles/PMC3017490 (pmc.ncbi.nlm.nih.gov)
- https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12152093/ (ncbi.nlm.nih.gov)