Changes

During cold winter periods or during warm periods in summer the difference in temperature inside cars and on the street becomes rather big. In summer this is mainly true in countries where many cars are equipped with air conditioning installations. On a longer distance this requires strongness from hitchhikers. During a whole day of hitchhiking - when one gets perhaps ten rides or even more - there is a constant change of temperature on the street and inside the cars. This rhythm might easily lead to a sore troath and coughing - especially when combined with (active or passive) smoking.

=== Heat ===

During very warm periods in summer, or in warm exotic countries, one should protect oneself against excessive heat from the sun. Sometimes a place in shadow is not available, and waiting times are not always reliable. A simple cap would help prevent from burning the neck. Also arms and legs can be vulnerable to the heat of the sun. Make sure to take enough water.