Thank you for asking Healthcare majic. My name is Dr Ehsan Ullah & I have gone through your query. Spray tanning is although believed to be safe as compared to other methods of Sunless tanning procedures like Tanning beds etc but still there are some health related aspects related to spray Tanning. Professional spray tanning products contain a Chemical (carbohydrate) which is called dihydroxyacetone, or DHA. This substance is derived from either glycerin or plant sources, and reacts with your skin’s amino acids to create a sunless glow. Though DHA is considered safe for external use, FDA has concerns regarding this due to potential health risk to your lungs when inhaled. so so if your friend has asthma, spray tanning may not be your best option for a healthy, sunless glow. Even if She haven t had asthma, but still begin coughing or feel out of breath shortly after a spray-tanning session, then should opt for an alternative sunless tanner like Lotions or gels precaution: Make sure a salon or spa attendant offers you a protective mask and applies the spray tan in a well-ventilated area. another health aspect is of Allergic reaction (Specially contact dermatitis) so do a patch test on the inside of your wrist, especially if you ve had a previous allergic reaction to self-tanning products, body treatments or cosmetics although shivering has multiple causes but This shivering can be due to allergic reaction but allergic reactions have other symptoms too like itching, skin rashes , sneezing ... if there are allergic symptoms then anti allergic drugs can relieve this condition like Claritin but If her shivering persists and she can t cold up then she needs an immediate consultation of physician to role out other causes of Hope this may help you. Let me know if anything not clear. Thanks.