In terms of holding hot objects, check out the answer on asbestos hands. If you mean weaning yourself into somewhere that is hotter (like a hot country) then yes, it is possible…
Each of us has a different tolerance to heat; some like it hot, some like it cold. There are a variety of reasons for our individuality: genetics, age, psychology and fitness. You can’t do much about how you are genetically predisposed to the hot or cold, neither can you do anything about your your age (the elderly and very young are less able to withstand hot temperatures). There are, however, some things you can do.
When we go somewhere hot (say, a sauna), we sweat more, our heat rate increases and our skin flushes. These are all ways that our body prevents us from overheating (see thermoregulation homeostasis for more on this). With time, your body will adapt (‘learn’) to become more efficient at doing these heat dispersing responses – you are effectively ‘training’ your body to deal with the heat. At the same time we will be psychologically learning to get used to hot temperatures. This is likened to getting used to learning to drive – it gets less scary the more you practice.
Also, if you are physically fit you are better able to tolerate high temperatures. People who have done lots of physical training will have hearts that are better at pumping blood, skin that is better at sweating efficiently, and a blood vessels can bring blood to the surface (‘flush’) with ease. So if you get yourself fit, you will find the heat easier.
So whether you are thinking of a regular sauna session or a holiday in a hot country, it is very possible to wean yourself into sustaining higher temperatures: don’t sweat it. Just do it slow and drink plenty of water.
Question from@qt2312 via Twitter
Answer by Dr Stu