Insects can be a problem. They may need to carry heavy items such as backpacks or rafts for long distances. The work is hard and the hours are long. Guides risk injuries and physical tiredness. City tour guides also work under various weather conditions.
Tour buses are often climate-controlled.
However, many city tours involve walking and exposure to the weather. Guides may stand or walk for much of the day. Recreation work is seasonal, so many guides work at two jobs. Some guides have enough knowledge to lead both summer and winter recreation trips. Most recreation guides are expected to supply their own equipment.