TLV stands for Threshold Limit Value and compares a person's current heart rate with their maximum sustainable heart rate.


On the FireHUD Platform, TLV stands for Threshold Limit Value and compares a person's current heart rate with their maximum sustainable heart rate. TLV is suggested as an indicator in effectively recognizing excessive heat strain according to the American Conference of Governmental Industrial Hygienists (ACGIH). It is calculated using the formula below: 



TLV is a percentage, and a TLV above 100% is considered unsustainable. The table below shows some example calculations. As can be seen in the table, the higher a person's heart rate and age, the higher their TLV will be.