Manual handling injuries are a major occupational health problem. The risk factors associated with manual handling in hot and cold environments were identified as a gap in knowledge under the Health and Safety Executive’s priority programme for musculoskeletal disorders (MDS’s). At present the manual handling guidance does not offer specific guidance regarding manual handling in non-neutral thermal environments other than to say that extremes of temperature and humidity should be avoided. Two experiments were designed to assess the effects on nonneutral thermal environments on manual handling. The thermal environments for this study are defined as manual handling events that occur within sub-ranges of a 0°C to 40°C range. For the purpose of this study a cold environment is defined as between 0°C - 10°C (44% - 60% relative humidity) and a hot environment is defined as between 29°C - 39°C (25% - 72% relative humidity). The results and implications of this experimental work are discussed in this report.