Minor Heat Syndromes (and Mis-nomers)

Heat syncope (fainting) is due to dilation (enlargement) of the veins and small blood vessels – blood can ‘pool’.  This is obviously worsened by dehydration.  A similar mechanism explains why athletes can ‘faint’ in the post-race hot shower: lack of blood circulation due to the ‘calf pump’ stopping and dilation of veins from heat.  Having said this many people who faint post-exercise have normal/expected CBTs.  Obviously there can be other more concerning causes of syncope/fainting.

The best avoidance of cramps is adequate training – working muscles way past exhaustion will cause cramps despite normal CBT, adequate hydration and electrolyte levels.