Let me introduce you to sambal, extremely spicy sauce with a rich seafood taste. Also for the quick research on dealing with spiciness skip to the bottom paragraph.
“Sambal is a hot sauce or paste typically made from a mixture of a variety of chili peppers with secondary ingredients such as shrimp paste, fish sauce, garlic, ginger, shallot, scallion, palm sugar, lime juice, and rice vinegar or other vinegar.”

Sambal in a glass jar. (Jaclynn Seah, 2015, The Occasional Traveler)
Because of its high fat content, in mild climate like Bend, Oregon it solidified. This solidified chunk looked like two large meat piece with sambal on top.
Well I was hungry so I thought “lets microwave these two tasty meat piece, and add rice on it.” Which I did and for some reason not realizing the sauce has melted completely (because there’s no meat, just pure sambal). I added rice, mixed it and in my blind hunger ate the rice with a chunk of the sauce.
The first bite made me realize that it was extremely spicy and my stomach immediately got hot. Then what had transpired just clicked in my mind and a tinge of regret for using the valuable sauce in one go. I finally finished it, the entire experience was a combination of pleasure and pain. Well mostly me burning my mouth and stomach. So I researched on journals on how to deal with the pain swiftly.
The spiciness of sambal or other chili sauce variants is capsaicin which is a vanilloid compound. This causes heat hyperalgesia a painful feeling akin to burning and heat sensitivity although mechanical hyperalgesia was not linked (Baad-Hansen et al, 2003). Because vanilloid compound which binds to transient receptor potential vanilloid type 1 (TRPV 1) that responds to heat and acidic pH stimuli (Pingle et al, 2007). So I thought it was acidic and looked to see if antacid will help. Unfortunately since capsaicin does not easily dissociate in water, this is difficult to determine. So I needed more research and looked up capsaicin interaction with antacids. I did not find much info on oral intake, so I will generalize findings from dermal exposure of capsaicin. Turns out there is some conflicting information regarding the effectiveness of antacids in dealing with pain, one study by Barry et al (2008) compares Mg-Al antacid, lidocaine gel, baby shampoo, milk, and water which results in no difference in pain relief for capsaicin exposure and noted that time is the best cure. While another study by Lee and Ryan (2003) noted that Mg-Al antacid helps a little bit. I was wondering then how fast does capsaicin go away if left alone? Well a pharmacokinetic analysis of capsaicin showed rapid plasma level reduction, with a mean population elimination half-life of 1.64 hours (Babbar et al, 2009). So pretty quick. According to Capsaicin MSDS Sheet it has oil/water partition coefficient of 3 which meant capsaicin is far more soluble in oil than water, which explains the popularity of milk (with casein explanation being suspect and without supporting evidence) as it contains ~3% fat. Sucrose water are also known to alleviate the pain (Nasrawi & Pangborn, 1990).
TLDR; swish your mouth with warm milk + butter mix or oil + water mix and spit. Then swish with crushed antacid and spit again. Drink sugary stuff. After 1 hour eat antacid to alleviate some stomach pain if needed.
References
Pingle, S. C., Matta, J. A., & Ahern, G. P. (2007). Capsaicin receptor: TRPV1 a promiscuous TRP channel. In Transient Receptor Potential (TRP) Channels (pp. 155-171). Springer, Berlin, Heidelberg. https://link.springer.com/chapter/10.1007/978-3-540-34891-7_9
Barry, J. D., Hennessy, R., & McManus Jr, J. G. (2008). A randomized controlled trial comparing treatment regimens for acute pain for topical oleoresin capsaicin (pepper spray) exposure in adult volunteers. Prehospital Emergency Care, 12(4), 432-437. https://www.ncbi.nlm.nih.gov/m/pubmed/18924005/?i=5&from=/20579556/related
Lee, D. C., & Ryan, J. R. (2003). Magnesium–Aluminum Hydroxide suspension for the treatment of dermal Capsaicin exposures. Academic emergency medicine, 10(6), 688-690. https://www.ncbi.nlm.nih.gov/m/pubmed/12782534/?i=12&from=/20579556/related
Babbar, S., Marier, J. F., Mouksassi, M. S., Beliveau, M., Vanhove, G. F., Chanda, S., & Bley, K. (2009). Pharmacokinetic analysis of capsaicin after topical administration of a high-concentration capsaicin patch to patients with peripheral neuropathic pain. Therapeutic drug monitoring, 31(4), 502-510. https://www.ncbi.nlm.nih.gov/m/pubmed/19494795/?i=14&from=/20579556/related
Baad-Hansen, L., Jensen, T. S., & Svensson, P. (2003). A human model of intraoral pain and heat hyperalgesia. Journal of orofacial pain, 17(4). https://www.ncbi.nlm.nih.gov/m/pubmed/14737878/?i=28&from=/20579556/related
MSDS Sheet of Capsaicin http://www.sciencelab.com/msds.php?msdsId=9923296
Nasrawi, C. W., & Pangborn, R. M. (1990). Temporal effectiveness of mouth-rinsing on capsaicin mouth-burn. Physiology & behavior, 47(4), 617-623. https://www.sciencedirect.com/science/article/abs/pii/003193849090067E