In a crossover design we investigated cardiac autonomic responses (heart rate variability, HRV) to isometric handgrip exercise (IHG) in cold (4°C) and temperate (24°C, temp) conditions in 20 men that assumed the supine position for 30min in an environmental chamber. After a 5min rest, subjects performed 3min of IHG followed by a 3min recovery period (REC). During REC, the low frequency of HRV was lower while the high frequency and the square root of the mean squared differences of successive NN intervals were higher (P<0.05) than the rest in the temp compared to a full recovery in the cold. In conclusion, recovery from concurrent cold exposure and exercise impairs cardiovagal modulation which may precipitate cardiac events.