Does heat affect football performance?

To contribute into this discussion we have analyzed performance data during the 2014 FIFA World Cup BrazilTM in relation to environmental heat stress. A summary of the findings is presented in this table. 

For the abstract please visit BJSM home page http://bjsm.bmj.com/content/early/2015/02/17/bjsports-2014-094449.abstract 

Soon, the full paper will have open access.