AS Britain's workers find themselves in another August, the TUC is calling for a legal maximum for workplace temperatures.

While there is a legal minimum temperature below which no one should have to work, there is no equivalent if it gets too hot.

Too much heat can cause fatigue, extra strain on the heart and lungs, dizziness and fainting, or heat cramps due to loss of water and salt.

Hot, dry air can increase the risk of eye and throat infections, and breathing problems such as asthma and rhinitis.

The TUC is calling for a maximum working temperature of 30 degrees C, or 27 degrees C for those doing strenuous work. When the heat hits the maximum, employers should reduce the temperature with, for example, fans or air conditioning.

Workers, whose exposure to heat cannot be reduced, should be provided with adequate breaks and offered job rotation. Hot temperatures cause injuries and illness at work. Employees suffering in sweltering workplaces run the risk of heat stroke and dehydration, tiredness leading to accidents, irritability and the threat of violence, and higher stress levels with enhanced risks of mental and physical illness.

TUC general secretary John Monks said: "It is farcical that we have a legal minimum but no legal maximum for workplace temperatures.

"Extreme heat can be just as dangerous as extreme cold."